An Italian man with a fetish for cutting off pieces of women's hair has been convicted of killing and mutilating his neighbour in the English coastal city of Bournemouth.

A jury at Winchester Crown Court in southern England found 39-year-old Danilo Restivo guilty of entering Heather Barnett's apartment, bludgeoning her with a hammer and cutting her throat in November 2002.

Restivo was due to be sentenced on Thursday, where he could face life imprisonment for murder.

But Italian authorities were reportedly preparing to pursue his extradition.

The ritualistic murder, which involved cutting off the victim's breasts and placing hair in or underneath her hands, echoed the 1993 slaying of a teenager in the southern Italian town of Potenza.

Elisa Claps' decomposed body was discovered in March 2010 in the hard-to-reach garret of the Most Holy Trinity Church in Potenza, with strands of her own hair in her right hand. Restivo, who had long been a suspect in both cases, was arrested two months later.

Restivo has denied wrongdoing, claiming he'd been framed, but did acknowledge routinely cutting off pieces of women's hair, prosecutor Michael Bowes said.

In Bournemouth alone, Restivo was accused of taking hair from 15 women on public buses, including a schoolgirl who said she'd felt her hair being pulled and turned around to find Restivo's face very close to hers.

In an incident dating back to 1992, a woman was sitting in a movie theatre in Potenza when she realised that the man sitting behind her had cut about 10 centimetres of her hair. Her fiance turned around to see a man he identified as Restivo masturbating.

Bowes, the prosecutor, had told jurors that Restivo's sexual obsession with hair was a key part of the case.

"It is quite plain he does have this propensity, or fetish, for cutting hair from women without their consent," Bowes said. "It is understood that he admits this conduct, both in Italy and in England. This is a big part of the equation and is highly probative in establishing that it was Danilo Restivo who murdered Heather Barnett."

Authorities in both Italy and Britain had long considered Restivo as a suspect. In 1995, he was convicted of giving Italian police a false alibi in relation to the Claps case. British investigators became suspicious of him shortly after Barnett's murder, when they visited his house and found his shoes wet and smelling of bleach.

Restivo was repeatedly put under surveillance, and British detectives travelled to Italy to gather testimony from women who'd had their hair cut in unusual or suspicious circumstances, But it wasn't until after the discovery of Claps' body that UK authorities felt confident enough to charge him.

Restivo is still wanted in Italy in relation to the Claps case.

Allegations include manslaughter, sexual violence and concealing a corpse.