Former FTX CEO Sam Bankman-Fried has rebuffed attempts from the top members of the Senate Banking Committee to get him to testify, despite a willingness to participate in several other interviews and a similar hearing in the House of Representatives.

“We have offered Sam Bankman-Fried two different dates for providing testimony before the Senate Banking, Housing, and Urban Affairs Committee, and are willing to accommodate virtual testimony,” panel Chairman Sherrod Brown (D-Ohio) and ranking Republican Sen. Pat Toomey (R-Pa.) said Monday in a joint statement. “He has declined in an unprecedented abdication of accountability.”

Bankman-Fried, who has made a number of remote public appearances in recent days and will testify at a House Financial Services Committee hearing this week, didn’t immediately respond to a request for comment about the Senate complaint.

Earlier on Monday, he told a Twitter Space that he would be testifying virtually before the House committee because he is “overbooked,” and had some concerns about his security were he to travel from The Bahamas, where he resides, to the U.S.

“I'm quite overbooked and was not planning to be testifying until like very recently,” he said.

The statement argued that congressional oversight only works when the CEOs, regulators and other government officials they invite to testify actually show up.

The lawmakers said Bankman-Fried’s counsel has “stated they are unwilling to accept service of a subpoena.” So the lawmakers will “continue to work to have him appear.”

Their earlier statement on Dec. 8 said that the collapse of the company Bankman-Fried founded and ran “has caused real financial harm to consumers,” and the lawmakers wanted answers from him about his “misconduct at FTX.”