THE Tate was severely reprimanded by the Charity Commission yesterday for paying more than £600,000 for an artwork by Chris Ofili while he was one of its trustees.

Ofili, who made his name by attaching blobs of elephant dung to canvases, was among numerous artist-trustees who benefited from the sale of their work to the gallery because the Tate’s “conflict of interest policies” were not in line with established good practice, a report has concluded.

To the commissioners’ astonishment, several of the trustees did not even bother to absent themselves from the meetings at which the acquisition of their work was discussed, and did not complete the trustees’ register of interests.

After an in-depth review lasting ten months, the commission, the independent regulator for charitable activity in England and Wales, ruled that the Tate had bought art from serving trustees without the legal power to do so. According to charity law, a benefit to a trustee needs to be cleared by the Charity Commission.

Sir Nicholas Serota, the Tate’s director, has accepted the criticisms and vowed that the gallery’s activities would be whiter than white in future. Although he acknowledged that the trustees should have left the room when their purchases were being discussed by colleagues, he said that none of the gallery’s trustees was aware of the charity law. Nor, he added, were officials at its funding body, the Department for Culture, Media and Sport, or those at the National Audit Office, which audited the Tate’s accounts every year.

But the Tate’s 12 trustees — including three artists, each appointed by the Prime Minister — are required to follow principles established by the Nolan Committee in the conduct of public bodies, including the declaration of trustees’ interests.

Sir Nicholas said: “It was clearly a general oversight. Ignorance is no excuse in the face of the law.”

Calling for “significant improvements” to be made, Andrew Hind, chief executive of the Charity Commission, said: “We found serious shortcomings in the processes for managing conflicts of interest and inadequate recording of decision-making. In any charity we would be concerned that such basic matters were neglected but, in a charity of the size and stature of the Tate, we are very disappointed.”

Although the Tate had insisted initially that it only acquired works by trustees in “exceptional circumstances”, The Times disclosed last year that there have been numerous examples.

The report has now confirmed those purchases.

In 1997 the board acquired Knowing — a painting of household items such as a torch — by Michael Craig-Martin, a trustee between 1989 and 1999, for £20,000.

There were also two works by Bill Woodrow, acquired from him in April 1997 for £20,000, while he was a trustee between July 1996 and 2001.

Although Ofili absented himself during talks on acquiring his work, the commission said it was particularly alarmed by the purchase. The artist was a trustee from November 2000 until November 2005. The Upper Room, a series of 13 paintings of monkeys with reliefs of dung that is displayed in rows to suggest a simian Last Supper, was acquired from his dealer, Victoria Miro, in 2004 for about £600,000, only months after it had been claimed that the Tate could no longer afford to buy works by the artists that it had helped to make famous.