The Tate has denied claims by a BBC programme that it paid a multi-million pound ransom to recover two stolen Turner paintings.
The paintings were stolen in 1994 and recovered several years later
Undercover Art Deal - to be screened on Wednesday - claims payments of around £3m were made to secure the return of the artworks, which was stolen in 1994.
However, a Tate spokeswoman insisted the money was paid for information and that "no ransom was paid".
A BBC spokesman said the corporation stood by the forthcoming programme.
He added that the documentary had been through "the usual rigorous editorial procedures".
£24m insurance tag
The two works - Shade And Darkness: The Evening Of The Deluge, and Light And Colour (Goethe's Theory): The Morning after the Deluge - were stolen from the Schirn Kunsthalle in Frankfurt in 1994 while on loan to the exhibition Goethe And The Visual Arts.
The paintings had been insured for £12m each.
Three thieves and a driver were arrested in 1995 and convicted in Germany in 1999.
Following the theft, the Tate made a claim and the insurers settled for the full insured sum of £24m, a move which meant the title to the paintings passed to the insurers.
But this was subject to an agreement that the Tate should have first option to repurchase them if they were recovered.
By 1998, the Tate had become concerned that the paintings had not been recovered and, as a result, a large amount of money in the insurance fund was lying dormant.
A deal was struck whereby the Tate bought back the insurers' title for £8m.
The first painting was recovered in July 2000, but Tate officials did not announced the news until December 2002, when the second painting was retrieved.
A Tate spokeswoman confirmed the gallery gained authority from the government and High Court to use funds to aid the return of the works, but insisted that money was only paid for information, not directly to criminals.
"What we are absolutely clear about, and what was explained at the time, is that no ransom was paid," she said.
She added that the case had been a "one-off" and the only major theft the Tate had suffered.
"The Tate acted throughout the investigation with the assistance and advice of the Metropolitan Police and dealt with a reputable German lawyer.
"The Tate obtained authorisation from the appropriate British and German authorities for all payments made by it to the German lawyer.
"The Tate paid money in the course of the negotiations for information that led to the recovery of the paintings and for the incidental expenses of recovery."