Culture Secretary Tessa Jowell chose not to attend Cabinet talks on Iran since 2003 due to her husband's business dealings, it has emerged.
Ms Jowell has been kept out of Iran talks for three years
Following a Sunday Mirror report, the Department of Culture, Media and Sport confirmed Ms Jowell did not have access to confidential documents on Iran.
This was after David Mills allegedly tried to use his wife's position to sell passenger jets to Iran in 2003.
Ms Jowell has been under fire in recent weeks over her links to his finances.
Mr Mills wrote to then-foreign office minister Baroness Symons for her opinion on the jet deal after meeting her at a dinner. The letter prompted complaints of cronyism.
The government said the letter was dealt with like any request for assistance, and Mr Mills said he had done nothing wrong.
The Department of Culture, Media and Sport spokesman said Ms Jowell had at the time volunteered information about the situation.
She had a conversation with the permanent secretary and "arrangements were put in place to make sure there were no conflicts of interest", the spokesman said.
The deal fell through after the US banned exports to Iran.
Italian prosecutors on Friday asked a judge to put Mr Mills on trial over claims that he received £344,000 from Italian PM Silvio Berlusconi for giving evidence about him in a trial.
Both Mr Mills and the Italian leader have denied the allegations.
Ms Jowell, who has separated from Mr Mills amid the current row, has been cleared by Tony Blair of breaching the ministers' code of conduct in the affair.