Lord Myners, the minister who signed off Sir Fred Goodwin's £16m pension, was embroiled in another controversy over a multi-million pound payment during his time as chairman of the Tate Gallery, it has emerged.

Lord Myners faced questions over £3m ransom for stolen Turners

Following the theft of two Turner masterpieces in 1995, Lord Myners denied point-blank that a ransom had been paid for them when they were recovered in 2002.

It later transpired that the gallery had paid out £3.1m to a German lawyer acting as a middleman for the thieves, and had even gone to the High Court to seek permission to use charitable funds to do so.

Michael Daley, director of the art conservation group ArtWatch, suggested Lord Myners was being "either incredulous or disingenuous" when he said in a letter in 2005 that no ransom had been paid for Shade and Darkness and Light and Colour.

Lord Myners is facing a similar accusation over his claims that he was unaware that an £8m pension top-up which enabled Sir Fred Goodwin to start claiming his £693,000 pension from the age of 50 was a "discretionary" payment. Sir Fred has claimed Lord Myners agreed to give him the extra money in lieu of a severance payment.

Mr Daley challenged Lord Myners over the ransom money after another Tate director admitted in a television documentary that a fee had been paid.

Lord Myners claimed he had been "given an undertaking" by the executives of the Tate that no ransom had been paid.

Mr Daley said: "Lord Myners told me the money had been paid as part of a sting operation by German police, but Sir Nicholas Serota, the director of the Tate, had stated quite clearly in court that the German lawyer was in touch with the people who had the paintings and they were prepared to hand them over in return for payment.

"Either Lord Myners was clueless or he wasn't being entirely straight with me."