James Thompson, a highly regarded former four-time governor of Illinois, came under fire on Wednesday by defence attorneys representing Conrad Black and other former Hollinger executives, with one suggesting that Mr Thompson had altered his recollection of events in testimony before the jury.

Edward Greenspan, Lord Black’s attorney, said it was a “remarkable coincidence” that Mr Thompson, who chaired the newspaper company’s audit committee, had missed several public disclosures of payments that lie at the heart of the government’s case against the former Hollinger chairman and chief executive.