The former chairman and chief executive of Brent Walker told a jury at Southwark Crown Court: 'I don't know the answers for it.'
It is alleged that Mr Walker, 65, masterminded a plan whereby money paid out for bogus contracts was laundered through international accounts and returned to Brent Walker to give the impression of rising profitability.
Peter Rook QC, prosecuting, asked Mr Walker if after all he had seen and heard in court over the past three-and-a-half months he would accept that money was leaving the group and coming back.
Mr Walker replied: 'I don't know the answers to it . . . If the people were here who were doing these deals they would be able to give the answers.'
Mr Rook asked him: 'Is not the truth of the matter you would have to be involved in relation to the movement of money?' Mr Walker, who claimed his signature had been forged on company letters, replied: 'Whatever I signed for I was involved in and I am happy to discuss it.'
The court heard that a flow chart showed a total of pounds 1m leaving Brent Walker, going to a company called Universal Talent Management and on to one of Mr Walker's offshore accounts, where he was sole signatory, before being returned to the company.
Mr Walker, of Fobbing, Essex, and the former group finance director Wilfred Aquilina, 42, of Barnes, south-west London, jointly deny conspiracy to falsify accounts, two offences of false accounting and one charge of theft.
Mr Walker alone denies three offences of theft while Mr Aquilina also denies another charge of false accounting.
The trial continues.