Curse of the Gem of Tanzania - a 10,000 carat, £15million ruby
The plot includes a colossal ruby called the 'Gem of Tanzania', the Crown Jewellers, an African coup, diamond smuggling and a Hollywood star.
It involves murky allegations of theft and dodgy documents.
And it also entails yet another burden on the poor British taxpayer.
You might, therefore, expect this exotic trail of intrigue and colourful characters to lead us to the Tower of London, say, or a Swiss bank.
The Gem of Tanzania, a giant ruby at the centre of a money mystery that has left 530 workers without a job
Instead, I have arrived at an industrial estate on the edge of the Shropshire town of Shifnal.
It's not exactly King Solomon's Mines. A couple of bored guards kick their heels outside a large yard full of redundant vans, diggers, cranes and bulldozers.
A train rattles past on the far side of an office building which shows few signs of life.
Until a few weeks ago, this was the headquarters of one of the largest employers in the area.
Now, its 530 workers have been thrown on the scrapheap, many voicing angry allegations about the management.
Meanwhile, the taxpayer is landed with another financial disaster and the administrators are selling off the JCBs and the Rollers and trying to salvage what they can from the financial wreckage.
And, right now, they are pinning their hopes on the last thing you would expect to find at a defunct building firm - a huge uncut ruby known as the 'Gem of Tanzania'.
Richard E Grant was asked by one of the ruby's owners to help promote a 'cure' for Aids based on goat serum.
Also known as the 'Star of Zanzibar' (although it has nothing to do with Zanzibar), it is said by some to be the most valuable ruby on the planet. One valuation describes it as a 10,725-carat specimen worth £15million.
So how on earth has it ended up in the hands of a roadworks operation in Shifnal? And why is everyone being so shifty about it?
Few people had ever heard of this mysterious rock three weeks ago when a construction firm called the Wrekin Group went bust.
With the British economy in freefall, this might not have been national news but it was a serious shock to Shropshire, where the majority of the 530-strong workforce were based.
Until a few years ago, Wrekin had been a thriving £100million family-run company specialising in unglamorous civil engineering - road repairs, roundabouts, car parks. .. that sort of thing.
The company had a loyal, happy workforce and an honourable reputation.
Then the founding father retired, new executives came along with bright, bold ideas (they even bought a company plane) and things started going downhill.
A recent takeover by a Uttoxeter businessman called David Unwin created an illusion of renewal but the decline continued until, in the middle of last month, unpaid creditors started hammering on the door.
Wrekin's bankers - the Royal Bank of Scotland - decided that it could throw no more of our money at the problem and called in the administrators.
At this point, it seemed like yet another sorry example of a British corporate failure, devastating for the workers but a familiar story.
Then an enterprising journalist on the local paper started looking more closely. Amy Bould, business editor of the Shropshire Star, was wading through the accounts to see where things had gone wrong.
Why had Wrekin recently reported a profit of £1.6m having lost £9m the year before?
Why had the company gone from a deficit of £8m to assets of £6m in just nine months?
And then she found an extraordinary little note hidden away in the accounts.
Wrekin's new owner had acquired millions of shares in the firm in exchange for a 'ruby gem stone known as the Gem of Tanzania'.
What's more, the stone had been valued at a staggering £11 million.
Considering the most expensive ruby ever sold fetched £2.5 million, this must be one hell of a ruby.
Until now, I had read about transactions like this only in history books. There was the medieval Irish noble, Baron Kinsale, who swapped his castle and ancestral estate for a magic stoat.
There were the Manhattes Indians who sold New York to Dutch explorers, in 1626, for a handful of beads.
To this long tradition of deeply strange deals must be added the acquisition of a collection of JCBs, Transit vans, 'Diversion' signs, hard hats and fluorescent bibs in exchange for a 5lb ruby, apparently fit for a sovereign's crown.
The discovery of the ruby has not really answered any questions, however. It has simply raised many more. And since it resides in the administrators' vault where no one can see it, the mystery continues.
Mr Unwin, who owns many companies, bought Wrekin for a nominal amount in 2007 through a property and plant hire outfit called Tamar Group of which he was the only director. He was then granted 11 million preference shares in exchange for the 'Gem of Tanzania'.
According to the annual reports of both Wrekin and Tamar, the ruby was deemed to be worth £11 million following a valuation by the 'Instituto Gemmologico Italiano' on 'August 31, 2007'.
This valuation has surprised many people, not least the Istituto (there is no 'n' in its name) Gemmologico.
'We have never seen this stone and we were closed on August 31, 2007,' says spokeswoman Lisa Greggio. 'This valuation is not true.'
When I ask Mr Unwin - via his solicitor, Derek Miller - to explain this confusion, he declines to comment.
Some former Wrekin workers, however, are not surprised. 'Is it any wonder the company's gone bust with directors like that?' asks former manager Neil Ainsworth.
'I mean, would you swap a multi-million-pound construction business for a ruby?'
But in recent weeks, Mr Unwin has produced another valuation, commissioned by a former owner of the ruby, which comes up with an even larger figure of between $20 million and $23 million.
Conducted in April 2004, the new valuation was produced by a diamond setter and gem collector called David Davis who is based in London's Hatton Garden. There's something a bit curious about this one, too.
'It was all very quick and it was a valuation purely for insurance purposes,' Mr Davis tells me. 'I am not saying it would fetch that amount at auction. It's very hard to put a value on something like that. It was a beautiful stone, though. I think it belongs in a museum.'
Mr Davis acknowledges that he is not a valuer of gems. However, his estimate of the ruby's worth was supported by a reference from Brian Dunn, senior valuer at Asprey & Garrard, the Crown Jewellers.
In the reference - written four years before - Mr Dunn vouches for Mr Davis's 'high degree of competence' in the subject.
Once again, things are not all that they seem. 'I wish I'd never given him that reference,' says Mr Dunn, who has since moved on from Asprey & Garrard to run his own operation.
'I did it as a favour. I can't even remember why. Davis is not a valuer but he has used my reference to support several huge valuations as if I support them, which I certainly don't. I haven't seen this ruby so I cannot value it but I would be very keen to.
'If these crystals are as good as some people say, this thing would have been cut down to gem stones by now. It sounds like it would make a very good doorstop.'
Even more interesting is the name of the ruby's owner at the time - Trevor Michael Hart-Jones. A former member of the Rhodesian military, he went on to pursue a range of dodgy business schemes in Africa.
One resulted in a 1985 conviction for diamond smuggling in South Africa. Another involved a failed attempt to buy the mineral rights of Sierra Leone from a rebel junta for $1billion.
In 2006, he attempted to recruit the actor Richard E. Grant to help promote a miracle 'cure' for Aids based on goat serum.
Having been born in Africa, Mr Grant was interested in any scheme to help the millions of Aids sufferers there, but soon realised that Mr Hart-Jones's scheme was unscientific humbug and alerted the BBC's Newsnight.
A humiliating expose and sting operation followed.
So can Mr Hart-Jones shed any light on the true story of the 'Gem of Tanzania'? Now living in a cottage in Sussex, he only adds to the mystery.
'This stone has been a jinx to me and nothing seemed to work for me after I bought it,' he says.
Mr Hart-Jones says that he bought the stone in 2002 for about £13,000 from a mining company called Ideal Standards.
The company, in which he had a stake, unearthed it near Arusha in northern Tanzania. He had it valued in 2002 by a gemologist from the Southern Eastern African Mineral Centre who, he says, put a figure of $21.3million on it.
He then brought the thing to London where Mr Davis performed his own valuation. Mr Hart-Jones says that he could not afford to insure it - a pity since, a year later, it was pinched.
'A friend approached me and said he had found a wealthy businessman who was interested in buying the ruby,' says Mr Hart-Jones. 'The man had already agreed to buy five diamonds from my friend and he wanted to see the ruby as well.
'My friend took the stone and handed it over to him and that was the last I ever saw of it. My friend was conned. He lost his diamonds as well. He went to the police about the diamonds and they took it further and I believe the man is serving a jail sentence for stealing the five diamonds.'
This staggering story gets stranger still. Mr Hart-Jones will not divulge the name of the friend or the alleged thief.
Now, if I had a stone worth up to £15million, I doubt I would cheerfully lend it a mate to show to a complete stranger. If I did, and the stranger pinched it, I think I would call the cops. Incredibly, Mr Hart-Jones says he did not.
'Because I'd handed the ruby to my friend, he might have been somehow implicated in the theft and I didn't want that to happen,' he insists. 'I did not want to put further pressure on him and his family. It's perhaps hard for you to understand but I just did not want to be part of the whole thing.'
He blames the ruby for subsequent downturns in his own career: 'There was never a positive side to this stone. Things started going wrong for me, business things, people pulled out of investments and that kind of thing.'
It certainly didn't help that Mr Hart-Jones's Aids 'cure' was rumbled by Newsnight a year later.
What happened to his 'stolen' ruby is anyone's guess but it seems that, by 2006, it belonged - quite legitimately - to a Cheshire property developer called Tony Howarth.
He is abroad and unavailable for comment when I call (Mr Hart-Jones, incidentally, says that he has never met Howarth).
According to the Financial Times, Mr Howarth sold the stone to David Unwin in 2006 as part of a land deal in which the gem was valued at £300,000.
Large, uncut crystals of this kind are hard to value, since so much depends on whether it can be cut into a single, large gem or will simply yield a large number of smaller and less valuable stones.
Often, it is impossible to tell until an expert cutter has applied that first, delicate blow from his chisel.
But one year later, Unwin's ruby had miraculously multiplied in value 37 times and was being used to prop up the Wrekin Group.
Today, there are 530 workers who want to know why a once-reliable and much-loved company has disappeared. Many are owed money.
'The company had been deducting my Child Support Agency payments from my pay packet for months and not paying it to the CSA,' says one former surveyor. 'Where's that money gone? I'm still liable for it.'
Others show me bewildering accounts showing recent sales of large machinery worth tens of thousands of pounds for as little as £1. Meanwhile, some sub-contractors face ruin if they do not get money Wrekin owes them.
Everything depends on what the administrators can get for the fabled 'Gem of Tanzania'. Is it worth £15 million or £300,000 or the price of a cup of tea?
Given the peculiar trail of this thing since it came out of the ground seven years ago, who knows?
But Mr Hart-Jones would appear to be right on one point. It certainly doesn't bring much good luck.
