A 57-year-old man is being hunted after a woman's torso was found in a suitcase in Peterborough.
Police have named the murder suspect as Vitautas Jokubauskas, a Lithuanian national.
Jokubauskas had been renting the property where the body was discovered with no arms, legs or head, Cambridgeshire Police said.
The body has not been identified.
However, detectives are also looking for a woman, thought to be Mr Jokubauskas' Lithuanian partner.
She is described as being about 40, slim and with black hair.
Detective Chief Inspector Adam Gallop said: "We are very keen to trace Mr Jokubauskas and we are clearly very concerned for the welfare of his partner, who has also not been seen for some time.
"Investigations are ongoing to determine where this murder took place."
Jokubauskas was last seen on 30 May when he was taken to work in Huntingdon by a friend.
Police think he might have fled to eastern Europe or Ireland, where he is known to have connections.
Officers were called to an address in Mayor's Walk, Peterborough, on Friday lunchtime after tenants complained of a "nasty" smell coming from a room that used to be occupied by the factory worker.
A cordon has been put up while forensic investigations are done.
The body has been removed from the house and a post-mortem examination will be done at Peterborough City Hospital on Monday.
Anyone with information should contact police on 101 or Crimestoppers anonymously on 0800 555111.
