Forensic tests expected to reveal vital clues in the hunt for a teenager rapist have drawn a blank, detectives revealed.

Police in Darlington probing the rape and sexual assault of a 19-year-old girl said that DNA examinations have proved inconclusive, and re-issued appeals to the public for information.

Earlier, examination of closed circuit television (CCTV) tapes from the town centre had revealed few new leads.

The girl was raped on Saturday, November 19 in the Neasham Road area of town, as she walked home from a night out in the Escapade nightclub with friends.

The teenager - who was wearing a brown fur jacket and long skirt - was grabbed from behind and forced to the ground shortly before 1am, as she walked past a dark alleyway that runs parallel to Neasham Road and Brunton Street. She was attacked despite screaming for help and attempting to fight off the man.

Her attacker is described as being about 5ft 6in, of medium build and clean-shaven. He had dark hair with a scruffy fringe and wore a blue, hooded jacket, blue jeans and white trainers.

Detectives last night urged anyone who may have any information from that night to get in touch urgently.

Detective Inspector Dave Wilkes, who is leading the inquiry, said: The DNA results have not revealed anything conclusive, so we would urge anyone who may have any information to come forward.

Anyone who has any information about the attack should contact Darlington CID on 0845 60 60 365.