Federal authorities in Boston have opened a criminal investigation into Steward Health Care, the CBS news network reported on Thursday.
It said federal prosecutors at the US Attorney's office in Boston are investigating Steward Health Care based on various allegations including fraud and violations of the Foreign Corrupt Practices Act.
Steward Healthcare filed for bankruptcy in early May.
CBC said the Department of Justice and Steward Health Care did not immediately provide comment.
The 9fin news website also reported about a Department of Justice criminal investigation in June.
Steward Health Care ran three hospitals in Malta, having taken over a concession which the government had handed to Vitals Global Healthcare. But a court last year struck down the deal after finding fraud, and the hospitals were returned to the government.
The government and Steward are currently facing off in international arbitration, the former demanding payment of funds handed for the management of the hospitals, and the latter seeking compensation for the abrogation of the concession agreement.
CBS News recalled how its own investigations had documented how private equity and other investor groups have siphoned hundreds of millions of dollars from community hospitals with devastating public health consequences.
Records reviewed by CBS News showed Steward hospitals around the country left a trail of unpaid bills, at times risking a shortage of potentially life-saving supplies.
"They've taken money away from these hospitals that provide needed care and they're using that money to line their own pockets." Massachusetts Gov. Maura Healey told CBS News in February. "I'm disgusted. It's selfish. It's greed."
The company previously told CBS News that executives always put patients first and said they "deny that any other considerations were placed ahead of that guiding principle." The company spokesperson said Steward "has actively and meaningfully invested" in its hospital system since its formation, including in Massachusetts, where it took over hospitals that were "failing" and "about to close."
Times of Malta and The Boston Globe on July 1 revealed records showing that Steward Health Care funded a campaign to smear former health minister Chris Fearne with fake corruption claims.
The campaign against Fearne was part of a wider €6.5 million secret operation authorised by Steward to target their perceived opponents in Malta and abroad.
The records were obtained by the Organized Crime and Corruption Reporting Project (OCCRP).