Ten former NFL players, including former Washington Redskins star running back Clinton Portis, have been charged in a brazen $3.9 million scheme to submit false claims to a health program run by the league, prosecutors said Thursday.

The players are accused in indictments filed in federal court in the Eastern District of Kentucky of claiming reimbursements for expensive medical equipment that was never actually purchased.

The equipment included hyperbaric oxygen chambers, cryotherapy devices, ultrasound equipment used to perform imaging on pregnant women, and even electromagnetic therapy devices used to treat horses, the government said.

The claims were typically for $40,000 to $50,000 apiece. The defendants allegedly fabricated documentation to submit for the claims, including invoices, prescriptions and letters of medical necessity, according to the Justice Department.

"By defrauding the plan and treating it like their own personal ATM machine, sadly, the defendants placed the plan's tax-exempt status at risk and threatened the ability of law-abiding former players to continue to receive tax-free reimbursements for legitimate medical expenses for themselves or their families," said assistant Attorney General Brian Benczkowski.

Prosecutors said some of the players acted as "ringleaders" in the scheme and recruited other former footballers, who paid them kickbacks and bribes out of some of the fraudulently obtained reimbursements.

The kickbacks reached more than $10,000 per claim.

The allegedly bogus claims were submitted to the Gene Upshaw National Football League Health Reimbursement Account Plan, which since 2006 has provided tax-free reimbursement for out-of-pocket medical costs of former players, their wives and dependents of up to $350,000 per player.

More than $3.9 million in false and fraudulent claims were filed, and the plan paid out more than $3.4 million from June 2017 through December 2018, according to prosecutors. Authorities said there were two conspiracies to defraud the plan involving different players.