"They [arrested officers] accompanied the armed mercenaries at the time of the crime," Marie-Michelle Verrier, the police spokeswoman, told the press.
She did not provide any further details concerning their involvement in the July 7 events.
Three other police officers have already been arrested in the assassination case, while nine more agents were detained and their homes were searched by the FBI, Verrier said.
Moise was shot dead at his residence on July 7. His wife, Martine, was wounded and airlifted to a US hospital. Haitian police have identified 28 suspects in the assassination, and 27 of them have been arrested, including 18 Colombians, five Haitians and three US citizens. The Pentagon has confirmed that seven of the Colombians had received US military training.