A Norfolk detective leading the investigation into the murder of a Norwich prostitute nearly two decades ago has revealed officers are following up new leads into her death.

Tomorrow marks 19 years to the day since the body of Natalie Pearman was discovered at Ringland Hills on the outskirts of Norwich.

The 16-year-old, whose mother Lin lives at Mundesley, had been working as a prostitute in Norwich's red light district and was last seen in Rouen Road a few hours before her body was discovered by a lorry driver in a lay-by at Ringland Road at 3.50am on Thursday, November 20 1992.

Natalie's case is one of a number of investigations which has been looked at by Norfolk Constabulary's cold case team, which was set up in August 2008 to investigate murders, missing people and serious sexual offences which have not yet been resolved.

Detective Chief Inspector Jes Fry, senior investigating officer in the case, said: 'We've been quite active on this inquiry over the past few months. We're progressing several fresh lines of inquiry and we've also received or had contact from several members of the public about things they observed around that time which have led to new inquiries.

'We continue to review the case and look for further opportunities to progress it. At this stage it's likely that we would need forensic evidence to advance the case significantly and that's where we've been concentrating.

'Some inquiries have been about people sighted in the area at the relevant time. People are still coming forward now with vehicles that they've seen or descriptions of people they've seen in the area in the 24 hour period after Natalie's death and with further investigation we've been able to identify and eliminate some of those people.

'These inquiries in themselves then reinvigorate discussion among the public and often lead to new information. We've been quite busy.'

Det Chf Insp Fry, who revealed three to four officers are working on the case, said they were currently looking at between 15 and 20 lines of inquiry relating to the investigation into Natalie's murder.

Some of those inquiries were new leads while others were revisiting information which had been put forward before in light of advances in technology and forensic science since the early 1990s.

Det Chf Insp Fry said: 'There are people who came into the investigation back in 19992/93 who were eliminated based on the scientific processes available at the time. We've reviewed these processes to see if they're foolproof and in some cases revisited using modern technology to ensure that they had been properly eliminated.'

Natalie was last seen alive in Rouen Road, Norwich at 1.15am the same day as she was discovered - five miles from where she had been working as a prostitute.

A post mortem examination revealed that she died from asphyxia. Forensic swabs revealed that semen was present in her body and on her under body garments and a DNA crime stain was obtained and loaded onto the national DNA database.

The subsequent investigation has interviewed over 4,000 people and a large number of men have provided samples for direct DNA testing. To date the DNA profile obtained from the semen has not been matched despite a general search of the English DNA database.

The case has never closed and been subject to reviews since 1992 with work still being carried out to identify whose DNA was found on Natalie.

Det Chf Insp Fry used the anniversary of her death to issue a renewed plea to anyone with information about Natalie's death to come forward and help the police solve this case.

He said: 'Somewhere out there is a vital piece of information. It's there for us to find I'm sure. I'm very keen that if anyone has any information whatsoever they should ring us and let us know.'

To view the cold cases log on to the website www.norfolk.police.uk, click on news and events and then cold cases.

Anyone with information about the case, or any of the other cold cases, should call 101 or email coldcaseteam@norfolk.pnn.police.uk