Simone Biles and others to sue FBI for $1bn over Larry Nassar investigation

Simone Biles, McKayla Maroney, Aly Raisman and Maggie Nichols testified before Congress last year

Women who say they were sexually assaulted by a disgraced US national gymnastics team doctor plan to sue the FBI for $1bn (£800m).

Claimants say the FBI mishandled credible complaints of sexual assaults by Larry Nassar.

They include Olympic gymnastics gold medallists Simone Biles, Aly Raisman and McKayla Maroney.

Nassar is serving up to 175 years in prison for molesting gymnasts.

The agency's own watchdog found the FBI disregarded allegations about Nassar and made early errors in its investigation.

Last year, a long-awaited report from the US justice department's Office of the Inspector General gave a scathing assessment of the federal agency's investigation into Nassar. Various missteps and cover-ups by FBI agents allowed Nassar's abuse to continue for more than a year after the case was first opened in 2015, the report found.

The majority of claimants in these suits say Nassar assaulted them after his abuse was reported to the FBI in 2015. Most were athletes with the USA Gymnastics programme or with Michigan State University, where Nassar maintained a clinic. The FBI field office Nassar's abuse was reported to took limited action and did not document any investigation or alert other authorities.

"My fellow survivors and I were betrayed by every institution that was supposed to protect us - the US Olympic Committee, USA Gymnastics, the FBI and now the Department of Justice," McKayla Maroney, an Olympic gold medallist, said in a statement.

"It is clear that the only path to justice and healing is through the legal process."

Two weeks ago, the US Justice Department decided not to prosecute the two FBI agents accused of mishandling the investigation.

The plaintiffs are seeking different amounts in damages but their total claims are expected to exceed $1bn.

The Collective Administrative Claims are being filed under the Federal Tort Claims Act, which allows people who have been harmed by negligent or wrongful actions of the federal government to seek compensation.

Under federal law, the FBI has six months to respond to the claims. Lawsuits may follow, depending on the FBI's response.

The FBI declined to comment and referred questions to remarks made by the agency's director following the release of the watchdog report, where he apologised for the FBI's handling of the Nassar investigation.