A double murderer who called himself the Scalp Hunter was told that he will die in jail yesterday after being convicted of butchering two women and dumping them in canals.
John Sweeney (54) was given a whole-life sentence at the Old Bailey for the murders of former girlfriends Paula Fields and Melissa Halstead.
Their bodies were discovered a decade apart in England and Holland and police now fear three other missing women may have suffered the same fate.
Sweeney, a carpenter, boasted of his violence in lurid paintings and verse found at his home.
Mr Justice Saunders said the gravity of the offences was exceptional and only a whole-life term would do.
He said: "These were terrible, wicked crimes. The mutilation of the bodies is a serious aggravating feature of the murders.
"Not only does it reveal the cold-blooded nature of the killer, but it has added greatly to the distress of the families."
The judge said the killings had been planned. "The method of disposal of the bodies demonstrates that there was a substantial amount of planning."
Now detectives want to know what happened to three other former girlfriends who have not been seen for many years.
A trainee nurse called Sue from Derbyshire was said to have gone to Switzerland in the late 1970s or early 1980s.
And they are also trying to trace two South American former girlfriends of Sweeney who have not been seen since the late 1990s.
Asked if the women were thought to have been murdered, Det Chief Insp Howard Groves said outside court: "We have some information which would suggest that is a possibility."
In addition to the two murders, he also launched an axe attack on a girlfriend, nurse Delia Balmer.
Some 300 paintings, wooden sculptures and poems were found at his home in 2001.
Sweeney was already serving four life terms imposed in 2002 for the attempted murder in 1994 of Miss Balmer.
The body parts of Paula Fields (31) were found in six holdalls floating in the Regent's Canal, London, in February 2001.