THE mystery surrounding the value of Wrekin Construction’s £11m Gem of Tanzania is set to be solved this week.

The ruby sitting on the books of the collapsed Wrekin Construction – contractors for St George’s Square – will be re-valued by the end of this week.

Ernst & Young, administrator to Shropshire-based Wrekin, has hired an independent valuer to establish the worth of the gem and expects to have an answer by the end of the week.

The mysterious ruby was used to strengthen the balance sheet of the construction company, turning net liabilities in March 2007 to £6m net assets by the end of that year.

Wrekin paid for the jewel by issuing £11m of preference shares to a company called Tamar Group, owned by David Unwin, who had recently bought Wrekin.

The company were awarded the £4m Kirklees Council contract to revamp St George’s Square.

Initially, doubts were cast over the existence of the ruby. But a large gem, roughly the size of a cricket ball, was handed over to Ernst & Young on March 20.

There are still questions about the ruby’s value, with experts suggesting they had never seen one worth so much. According to Christie’s, the highest price achieved for a ruby at auction was £2.6m in 2006.

A South African-born businessman, Trevor Michael Hart-Jones, said he had bought the gem for £13,000 in 2002.

He sold it to the director of a foreign exchange business, Tony Howarth.

Mr Unwin bought the ruby in 2006, according to the report, in a deal valuing the gem at £300,000, and the ruby was valued at that price on the balance sheet of Tamar that year.