BBC Chair Richard Sharp made "significant errors of judgement" in failing to declare his involvement in facilitating a loan for then-Prime Minister Boris Johnson shortly before he was appointed to the role, a committee of lawmakers said on Sunday.

Sharp, a former Goldman Sachs banker, has said he introduced Sam Blyth, an old friend who wanted to help Johnson, to a government official in late 2020, but his involvement went no further.

Blyth, who is a distant cousin of Johnson, went on to lend the former prime minister up to 800,000 pounds ($964,640), a media report has said.

Sharp has said, and reiterated to the committee when he appeared before it on Tuesday, that he was not involved in making a loan or in arranging a guarantee or any financing.

He said after seeking an introduction for Blyth, he had agreed with a senior government official to have nothing more to do with the matter to avoid any conflict of interest.

The cross-party parliamentary committee said Sharp's decision not to tell it or the appointment panel about the matter during the appointment process was a breach of the standards expected of individuals applying for such public appointments.

"Such a significant error of judgment meant we were not in the full possession of the facts when we were required to rule on his suitability for the role of BBC Chair," acting committee Chair Damian Green said.

Sharp should consider the impact his omissions would have on trust in him, the BBC and the public appointments process, the committee's report said.

The chair of the broadcaster, which is funded by a licence fee paid by TV-watching households, is appointed on the recommendation of the government.

A spokesperson for Sharp said: "Mr Sharp appreciates that there was information that the committee felt that it should have been made aware of in his pre-appointment hearing. He regrets this and apologises."

Sharp also apologised again to the broadcaster's staff for the distraction caused to the BBC.

The opposition Labour Party said Sharp's position was "increasingly untenable".

Britain's public appointments watchdog is also reviewing Sharp's appointment.

Government minister Andrew Mitchell told the BBC on Sunday: "We need this inquiry to take place but then I think it will be a matter largely for the board of the BBC to make a recommendation to government."

($1 = 0.8293 pounds)