POLICE in Darlington are asking a passer-by to help them by trace a thief.

The culprit broke into a lorry which was making a delivery in the town's Langdale Road and stole a Sony Ericsson mobile phone, a satellite navigation system and more than £200 cash.

When the driver returned minutes later and discovered the theft, he was approached by a woman aged about 30, who was slim and about 5ft 6in.

She said she knew who was responsible for the crime and offered a name for the suspect.

However, she did not leave any personal details about herself either with the victim or the police.

Investigating officers are now keen to speak to the woman who may be able to provide more clues to the incident.

The lorry driver described her as "attractive", with a tanned complexion and dark hair. The theft happened at about 7.20pm last Friday.

She is asked to call Darlington police on 0845 6060365 and ask for the investigating officers, PC Jillian Goold or PC Phil Muir