A psychiatric patient was charged Thursday with two counts of murder in the overnight stabbing deaths of two men who were also patients at an Australian hospital.

Police told the Melbourne Magistrates Court that Peko Lakovski, 49, armed himself with a large kitchen knife and stabbed his roommate and another man late Wednesday.

The three men, all convicted murderers, were patients at Thomas Embling Hospital, a secure facility that assists people from the criminal justice system who need psychiatric assessment or treatment.

Homicide Squad Detective Senior Constable Jamie Ronke said bloody clothing was found in the suspect's bedroom and police discovered a large knife in another area of the unit that appeared to have been used in the attack.

Victoria state Mental Health Minister Lisa Neville ordered an investigation into why the men were housed in a low-security unit, which provided kitchenettes and separate bedrooms in preparation for being released from the hospital.

The unit has 24-hour guards but no internal security cameras.