Former President Bill Clinton and Hillary Clinton, the 2016 Democratic presidential nominee, will testify in a congressional investigation into the late sex offender Jeffrey Epstein, a staffer said on Monday.

The decision could head off a planned vote in the Republican-led House of Representatives to hold the two prominent Democrats in contempt, which could lead to criminal charges.

The House Oversight Committee recommended last week that they be held in contempt for refusing to testify about their relationship with Epstein. The Clintons had offered to cooperate with the panel but had refused to appear in person, saying the investigation was a partisan exercise aimed at protecting Republican President Donald Trump.

"They told you under oath what they know, but you don't care. But the former President and former Secretary of State will be there. They look forward to setting a precedent that applies to everyone," the Clintons' deputy chief of staff, Angel Urena, said in a post on social media.

House Speaker Mike Johnson welcomed the news but did not say whether the chamber would drop its planned contempt vote.

"That's a good development," he said. "We expect everyone to comply with Congress's subpoenas."

Bill Clinton flew on Epstein's plane several times in the early 2000s after leaving office. He has expressed regret about the relationship and said he knew nothing about Epstein's criminal activity.