A Russian billionaire who reportedly worked closely with former Trump campaign chairman Paul Manafort took out ads in multiple major U.S. newspapers Tuesday, offering to be interviewed by congressional committees investigating Russia’s meddling in the U.S. election.

The House Intelligence Committee said it has yet to hear from Oleg Deripaska, a close ally of President Vladimir Putin, directly.

Deripaska made the offer after the Associated Press published a story detailing the $10 million lobbying contract he negotiated with Manafort for work to “greatly benefit the Putin Government.”

In ads published in the Washington Post and Wall Street Journal, Deripaska strenuously denied the AP’s report.

“I have never made any commitments or contracts with the obligation or purpose to covertly promote or advance ‘Putin’s Government’ interests anywhere in the world,” the ad read, calling the article “fake news.”

“I am ready to take part in any hearings conducted in the US Congress on this subject in order to defend my reputation and name,” it continued.

The witness list grows: Deripaska, Russian oligarch and one time Manafort business partner, offers to testify pic.twitter.com/qGqH33g5fg — Michael Isikoff (@Isikoff) March 28, 2017

Jack Langer, a spokesman for House Intelligence Committee Chair Devin Nunes (R-CA), told TPM that Deripaska has not contacted the panel.

“We haven’t heard from Deripaska to my knowledge,” he said in an email.

Manafort offered to be interviewed by the committee after the AP published its report. Carter Page and Roger Stone, two other former Trump campaign advisers who allegedly had ties to officials or operatives in Russia, have sent letters to the committee offering to be interviewed as well.

The House Intelligence panel’s investigation virtually ground to a halt this week, and none of those interviews appear to have been scheduled. Democrats and some Republican lawmakers charge that Nunes compromised the committee’s work with his overly close relationship to the Trump administration.