Hungarian police have launched a criminal investigation after unearthing several bodies on an island in Budapest, a police spokesman said on Friday, and a newspaper reported that the victims may have been buried alive.

The National Bureau of Investigation did not confirm the number of victims, and did not give further details.

"Several bodies were found and we are investigating homicide," police spokesman Laszlo Bartha said.

Daily newspaper Magyar Nemzet said police had been tipped off by a man who had escaped after being buried alive up to his chest.

A Serbian loan shark suspected of the murders had led police to the scene, in a forest in Csepel port, where they found four bodies, the newspaper said. The victims may have been buried alive and more could yet be found, it said.