Firm's £11m ruby no longer a gem

The stone, known as the “Gem of Tanzania”, had been bought by Wrekin Construction in 2007.

The Shropshire-based company collapsed last March with the loss of more than 300 jobs.

It said last year that the value of its ruby gemstone had been determined by a professional valuer at the Instituti Gemmologico Italiano based in Valenza, Italy, on 31 August 2007.

It has been alleged the gemstone was mined in Tanzania and brought into the UK by a South African entrepreneur later involved in a scheme to cure Aids with goat serum.

Wrekin Construction was also claimed to have used the stone’s 11m valuation to support the company’s creditworthiness.

But administrator Ernst & Young subsequently declared the 2kg – 4.41lbs – stone’s multimillion pound valuation and the documents that accompanied it were forgeries.

The ruby was sold to Pertemps Investments Ltd last week for only 8,010. More than 60 offers were made for the jewel.

When Wrekin went into administration, the company was due 2m from Government contracts but owed more than 3.5m in VAT and tax bills, according to the administrator.

The firm was established in 1960 and its work included motorway and highway construction, refurbishment work to canals, rivers, rail routes, rail infrastructure, sewers and drainage.

It remains in administration, Ernst & Young said.