U.S. Senate subcommittee is seeking FBI investigation of former U.S. Olympic Committee (USOC) chief executive Scott Blackmun for making "materially false statements" to lawmakers probing sexual abuse in gymnastics.

Republican Senator Jerry Moran, the chairman of the Senate subcommittee on commerce, and Senator Richard Blumenthal, the highest ranking Democrat on the panel, issued a joint statement on Friday saying they had referred the matter to the FBI.

The move comes after a damning report released on Monday that said the USOC failed to react swiftly when first warned of allegations surrounding former gymnastics team doctor Larry Nassar in 2015.

Instead, according to the report commissioned by the USOC and carried out by Boston law firm Ropes and Gray, they concealed the doctor's crimes until the scandal erupted into public view in late 2016.

Nassar was jailed for life earlier this year after abusing more than 250 athletes, inducing several stars of the United States' gold medal-winning teams at the 2012 and 2016 Olympics.

The senators cited Blackmun's written testimony to the subcommittee that when he heard of the allegations against Nassar in a July 2015 telephone call from then U.S. Gymnastics chief Steve Penny that he spoke to the USOC's "SafeSport staff" -- which oversees abuse claims in Olympic sports.

But they noted that independent investigators found no evidence supporting Blackmun's claim that he held a meeting with USOC staff to make sure the matter was properly pursued.

"The Subcommittee takes its oversight role seriously and it appears that Mr. Blackmun has made false claims and misled our Subcommittee -- harming the investigation and the ability to develop policy," the senators said. "Just as importantly, survivors of abuse have had to wait longer for the truth and longer for systemic changes to help prevent others from similar injury."

Blackmun stepped down in February amid stinging criticism of his handling of the case, not long after disclosing he was battling prostate cancer.