Italian investigators have provided UK police with more information on cases thought to be linked by a hair fetish.
The body of Ms Barnett was found clutching someone else's hair
The death of Heather Barnett, 48, found at her Bournemouth home in 2002, holding someone else's hair, was linked to an Italian teenager's disappearance.
Dorset police said their work in Rome has led to 28 Italian people reporting details of value to their murder case.
An appeal on Italian TV to trace Elisa Claps resulted in information which police said connects the two cases.
Mother-of-two Heather Barnett was found dead in the bathroom, of her home in Capstone Road, Bournemouth, by her children on 12 November 2002.
'Travelling on buses'
She had been stabbed several times, hit over the head with a blunt object and her body mutilated.
Despite extensive inquiries police have been unable to trace who the hair found in Ms Barnett's hand belonged to.
Miss Claps, 16, went missing from Potenza in southern Italy in September 1993.
Elisa Claps, 16, vanished in Potenza in 1993
Det Supt Phil James said: "Together with detective chief inspector Mark Cooper, we met senior members of the Italian DIA (anti-Mafia Police) and also member of the Italian judiciary in Rome.
An Italian version of Crimewatch, Chi I'ha Visto, led to five women reporting they had had their hair cut while travelling on buses.
Det Supt James added: "An appeal on the Italian programme in November 2006 resulted in Dorset Police being provided with the details of 28 people in Italy who have information of interest about the Heather Barnett case - or who have had their hair cut in unusual circumstances in various locations in Italy."