The Federal Bureau of Investigations is investigating the Commonwealth Utilities Corporation of the Northern Marianas.
The utility company has turned over financial records and other documents regarding federally funded projects to the FBI.
CUC Executive Director Tony Muna told the Marianas Variety that agency employees have been subpoenaed and questioned in the probe.
He says the investigation was initiated before he became executive director in May and does not cover only recent contracts.
Mr Muna says the information requested by the FBI has been provided.
He said CUC is an open book and has nothing to hide.