The Tory MP was interviewed for two hours at the headquarters of Customs and Excise in the City of London. The interview was pre-arranged and Mr Aitken left without any charges being made against him.
Mr Aitken was a non-executive director of the Lincolnshire-based firm BMARC which has been accused of exporting arms to Iran in defiance of a UN embargo. He resigned as Chief Secretary to the Treasury in July in order to sue a number of publications over the allegations. He said he was fighting the "cancer of bent and twisted journalism".
The Customs inquiry was announced earlier this year by the then President of the Board of Trade, Michael Heseltine. A report will be submitted to the Director of Public Prosecutions. Customs and Excise said: "We never comment on on-going investigations."
Mr Aitken later attended a Downing Street reception to celebrate Lady Thatcher's 70th birthday. Major John Thomas, the chairman of Mr Aitken's constituency association in Thanet South, shrugged off the report.
"It was said at the time that these Customs people were going to carry out an investigation and that he was one of the people they would be seeing. I would have thought it was a normal procedure at this stage," he said last night. "He said at the time that he was quite happy to answer any questions."Reuse content