The investigation was reopened in May on the instructions of the Deputy Prime Minister, Michael Heseltine, then President of the Board of Trade and reponsible for regulation of City affairs, according to the Sunday Mirror.
Mr Heseltine is said to have asked inspectors six weeks ago to reopen and broaden the timescale of the inquiry into the purchase and subsequent sale of shares in Anglia, which soared in value after a takeover bid.
Last year the inquiry centred on 50,000 shares which Lord Archer bought for an Iraqi friend, Broosk Fawzi Saib, which rose by pounds 80,000 when news of the takeover bid emerged. Lord Archer's wife Mary was a board member of Anglia TV at the time. She has since resigned.
While denying all wrongdoing, the millionaire and former deputy chairman of the Tory party apologised to his wife for making a "grave error". There was never any suggestion of wrongdoing on Lady Archer's part.
Mr Heseltine told Parliament last year that on the basis of the inquiry report - by an eminent barrister and accountant, Roger Kaye QC, and Hugh Aldous FCA - and legal advice, no action would be taken against Lord Archer.
Last night friends of Lord Archer, 55, said he was aware of the renewed investigation, but that it did not involve him.
The Department of Trade and Industry would only say: "It is not our usual practice to confirm or deny investigations into insider dealing."
The reopened inquiry will be able to examine Anglia shares bought by Karen Morgan Thomas, a stockbroker friend of Lord Archer, who met the novelist while she was raising funds for the Conservative Party.
Ms Morgan Thomas made a pounds 22,000 profit on her shares when they rose in value.
She has rejected allegations of insider dealing and said that she acted on the basis of a tip in a Sunday newspaper.Reuse content