Richards Butler is examining board minutes approving the purchase by SelecTV of shares in Wilton Group, a company chaired by Michael Buckley, who was also chairman of SelecTV until last week.
The minutes say the board agreed to proceed with the deal, with Mr Buckley abstaining.
At the time of the purported board meeting, 4pm on 16 December 1991, of the other four directors Allan McKeown was in Los Angeles, Peter Laister was also overseas, Michael Pilsworth was at a meeting of the trade body PACT, and Tony Charles was at the Groucho Club preparing for the office Christmas party.
Mr Pilsworth, managing director, said: 'We've asked our solicitors to investigate how SelecTV came to be the owner of 12 million shares in Wilton, of which he (Mr Buckley) is chairman.'
He said the company had now written off the pounds 230,000 investment in Wilton, which had interests in toys wholesaling, quarrying and property.
News of the fresh investigation emerged as SelecTV announced that its chief executive, Mr McKeown, had been exonerated by Richards Butler of allegations made last week by Mr Buckley when he was chairman.
The company, which makes Birds of a Feather and owns a 15 per cent stake in the broadcaster Meridian, admitted to 'certain minor technical shortcomings in the formal administration of the company' but said there was 'no substance in any of the allegations which have been made against Allan McKeown'.
It also confirmed that Tony Brook, former deputy chairman of TVS Entertainment, was to be the new chairman, replacing Mr Laister, who temporarily filled the chair. Further non-executive board appointments are expected.
Mr Buckley issued a statement last night calling for an independent firm of solicitors to examine the allegations he made, rather than Richards Butler.
Mr Buckley alleged in a writ last week that Mr McKeown had received rent for Mayfair office space used by SelecTV of twice the amount agreed by the board. Mr Pilsworth said the rent increases had been agreed but admitted they had not been minuted.
He also conceded that Mr McKeown had failed to declare an interest when SelecTV bought the television rights for the play The Big Love, which starred Tracey Ullman, who is Mr McKeown's wife.