A human skull found washed up on a beach on Tuesday was the first in a series of grisly discoveries that have left Victoria Police investigating five deaths.

By Saturday, along with the human remains found on North Shore beach in Geelong, two men had been stabbed to death and two bodies had been found in mysterious circumstances by distressed passersby.

On Saturday morning, a Port Melbourne man was charged with murder following the death of another man in Port Melbourne on Friday.

Hugh Brown, 44, faced Melbourne Magistrates Court on Saturday morning and was remanded to reappear on June 23.