Investigators believe 'Scalp Hunter' murderer John Sweeney (54), who murdered two of his girlfriends and tried to kill another, may be responsible for the slaying of more women.

Murder Squad detectives have released new photos of the 'Scalp Hunter' in the hope of receiving additional information about his movements across the UK and Europe during the 80s and 90s, in an attempt to uncover more possible victims.

The Daily Mail reports, that 'Sweeney was first arrested in 1994 after subjecting Miss Balmer to 48 hours of torture when she ended their relationship. He was granted bail by a magistrate and hours later attacked Miss Balmer with a knife and an axe before going on the run. He fled to Europe and it was not until 2001 that he was arrested as he left a London building site where he had been working.'

It was just a month ago, while still serving time in jail that Sweeney, a carpenter of Kentish Town, north London, was 'found guilty in the Old Bailey for the brutal murders of Paula Fields and Melissa Halstead after a joint EU Commission-funded operation by British and Dutch police,' reads the Daily Mail.

Miss Halstead, an American model who had been living and working in Holland, was discovered in a canal in Rotterdam in 1990, but it wasn't until her body was identified in 2008 that the link to John Sweeney was made. Melissa Halstead's sister Chance O'Hara, told the Old Bailey, "She told me if she ever went missing, that John Sweeney would have killed her." It was because Miss Field's disappearance was so similar to Miss Halstead's that he was prosecuted for her murder too.

It was when Sweeney, who used the aliases Joe Johnson, Joe Carroll and Scouse Joe, and spoke with a stutter, was convicted of the two murders recently, that Scotland Yard suspect him of killing three previous girlfriends and two German men, the Daily Mail says.

The Murder Squad detectives have also released gruesome artwork made by Sweeney in the hope that someone will recognise the persons in the paintings and drawings. The drawings seem to describe the conditions in which the women were murdered. Another drawing by someone else was found amongst his possessions marked 'London 1985' which has raised investigation.

There are three women still missing who are thought to have had relationships with the murderer. A Brazillian woman called Irani, and a Colombian woman known as Maria, went missing from north London in 1997 during the six years that he was on the run and in which he murdered Miss Fields.

The police forces are urging anyone who recognises the women in the paintings and drawings to get in contact.

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