The parents of a woman murdered in Norfolk in 2002 hope a recently-discovered notebook could hold the key to finding her killer.
Michelle Bettles was found strangled some 20 miles from Norwich, where she'd been working as a prostitute. She would have been 40 this year.
Her parents have found a book that belonged to Michelle's partner, Chris, and they hope some of the names and addresses in it might be of interest to the police.
Watch a report by ITV News Anglia's Malcolm Robertson
"It's like any tiny little bit of information. There are people out there now who could be married, got children, living a normal life. "17 years ago they could have been associated with Chris. Their name could be in that book. "All I would say to people is come forward because you never know you might get that knock on the door."
Michelle's body was found on 31 March 2002 in woodland by the side of a country track known as Rush Meadow Road in Scarning, near Dereham.
Michelle Bettles was 22 years old when she was murdered.
She was last seen in the red light district of Norwich during the early hours of Thursday 28 and Friday 29 March 2002 Easter weekend.
Michelle unusually had not kept a pre-arranged appointment with a regular client of hers.
They had arranged to meet close to her home address in the Dereham Road area of Norwich but she never kept the appointment.
CCTV footage shows Michelle walking along St Benedict's Street towards the city centre at 8.20 pm that night.
Clearly, for whatever reason, she had never intended to keep the appointment with the regular client since she was heading in the opposite direction to their pre-arranged meeting.