Ball was a beneficial owner of Fashion and Sport Ltd, a company that sold clothing brands and supplied stock to JJB, and was also associated with another company called Performance Brands.

The Serious Fraud Office (SFO) conducted a lengthy investigation beginning in 2009 into Ronnie's failure to declare his interest in contracts entered into by JJB Sports with these suppliers, as well as attempts by Ball and his business partner David Barrington to destroy evidence and mislead the SFO.

The fraud trial centred on payments received by Ronnie in late 2007 and during 2008, from companies run by Ball and Barrington, which had not been declared to the JJB board of directors. Ronnie, who was heavily indebted at the time with £11m owed to an Icelandic bank, Kaupthing Singer Friedlander, for his purchase of the sports retailer.

Ronnie was found to have worked with Ball and with Barrington to create false loan deals. His company Seacroft received a payment of £650,000 in February 2008 from Performance Brands and then two payments of $380,000 (£197,000) and $250,000 (£134,000) from Fashion & Sport in June.

When Ronnie was interviewed by the SFO, he claimed that the payments were loans for him and his wife, Helen, to buy ‘a very nice property’ in Florida. The court found that the loans were in fact private payments to Ronnie made without the knowledge of JJB’s board of directors.

Miranda Moore, acting for the prosecution, said Ronnie had failed to disclose to JJB’s board of directors that he had a financial interest in the deals.

‘Mr Ronnie had a number of opportunities to say: “Look, I’m going to do this”’ and tell them all about it. He never took that opportunity because he wanted to keep the money for himself,’ Moore said.

Following a trial at Southwark Crown Court, Ronnie was found guilty of three offences of fraud and two offences of furnishing false information.

Ball was convicted of two offences of attempting to pervert the course of justice, in relation to attempts to destroy digital material and to mislead the SFO during its investigation. He was acquitted of two offences of furnishing false information, and the jury were unable to agree in relation to a third count of furnishing false information.

Barrington was convicted of two offences of attempting to pervert the course of justice, also in relation to attempts to destroy digital material and to mislead the SFO when purporting to comply with notices served under S2 of the Criminal Justice Act 1987.

The trial heard evidence that Ball and Barrington had removed emails which related to details of the loans. They were also said to have falsified information about assets and liabilities which was provided to a bank used by Ronnie.

Ball and Barrington employed a computer engineer to wipe evidence from their systems after being tipped off that the contracts were being scrutinised. However, the engineer was so worried about what he found that he made a back-up of the files and handed it over to the SFO.

All three men will be sentenced at Southwark Crown Court on 12 December 2014.