The House January 6 committee has discovered that lawyers connected to Donald Trump sought to influence witnesses with job offers and advice including that it was OK to lie to investigators.

In an opening statement in Monday’s final hearing on Capitol Hill, Zoe Lofgren, a California Democrat, said: “We are concerned that these efforts may have been a strategy to prevent the committee in finding the truth.”

Lofgren was outlining findings detailed in the committee’s report into the attack on the US Capitol in Washington DC, which was released on Monday after a final hearing in which the committee voted to make four criminal referrals of the former US president and his associates to the justice department.

She said: “The committee found that Mr Trump raised hundreds of millions of dollars with false representations made to his online donors.

“Proceeds from his fundraising we have learned have been used in ways that we believe are concerning. In particular, the committee has learned that some of those funds were used to hire lawyers. We have also obtained evidence of efforts to provide or offer employment to witnesses.

“For example, one lawyer told the witness the witness could in certain circumstances tell the committee that she didn’t recall facts, when she actually did.”

The committee report says the lawyer also “instructed the client about a particular issue that would cast a bad light on President Trump”, saying: “No, no, no, no, no. We don’t want to go there. We don’t want to talk about that.”

Lofgren continued: “That lawyer also did not disclose who was paying for the lawyer’s representation, despite questions from the client seeking that information. He told her, ‘We’re not telling people where funding is coming from right now.’”

Efforts to contact and influence witnesses have been mentioned by committee members before, around an appearance by Cassidy Hutchinson, a former aide to Trump and his last chief of staff, Mark Meadows, which contained some of the most dramatic testimony of all.

Lofgren said: “We’ve learned that a client was offered potential employment that would make her quote ‘financially very comfortable’. As the date of her testimony approached, by entities that were apparently linked to Donald Trump and his associates, these offers were withdrawn or didn’t materialise.

“As reports of the content of her testimony circulated, the witness believed this was an effort to perfect her testimony. We are concerned that these efforts may have been a strategy to prevent the committee from finding the truth.”