Officials said Thursday they are investigating allegations that millions of dollars embezzled from Honduras' social security institute might have been used to finance the governing National Party.

The Public Ministry said in a statement that authorities were studying checks from supplier companies to the agency's director and his friends. The companies are alleged to have overcharged for supplies and then kicked back some of the money.

The ministry didn't say which party was being investigated in relation to the case, but the director of the National Anti-Corruption Council, Gabriela Castellanos, said three protected witnesses have said it is the National Party of President Juan Orlando Hernandez.

"The moment these witnesses, who are implicated in acts of corruption, told us they knew of the existence of checks written to the National Party, we put them before the Public Ministry," she said.

She said top businessmen, officials and politicians were involved in the alleged scam.

Asked about the investigation, leaders of the party said only that it would have to look into the allegations.

Opposition lawmakers have charged that the money financed Hernandez's successful election campaign in 2013.