A ruby worth £11m according to the books of a collapsed Shropshire civil engineering company was valued at £300,000 just a year previously, it has emerged.

The 'Gem of Tanzania' revived the balance sheet of Wrekin Construction, which went into administration last week. In 2006, the precious stone belonged to Tamar Group, a vehicle of businessman David Unwin.

Tamar’s 2006 books report a gem worth £300,000. nwin took over Wrekin in 2007, when it issued £11m in preference shares in return for the stone. Wrekin’s total assets, according to its 2007 accounts and including the £11m ruby, were about £28m.

Christie’s said the highest recorded price for a ruby was $3.6m (£2.6m) in 2006.

Financial Times