DETECTIVES who have been hunting a poison pen pervert on a housing estate for more than a year believe they could be on the verge of a vital breakthrough.

Officers are appealing for man they beleive has vital information about the case to come forward. Women and young girls in the Shepway area of Maidstone have been bombarded with obscene letters describing the writer's sexual fantasies.

Dozens of obscene letters have been found in public places over the months and are always directed at women and young girls. The man police think can provide key information is white and aged between 40 and 50.

A police spokeswoman said the man was always clean-shaven and had grey or blond light coloured hair that was recently shaven very short. He is of medium to proportionate build and normally had a brown and white Collie dog with him.

The spokeswoman added: "We believe this man could be a vital witness in the case and ask him or anyone who knows him to come forward."

A young girl found the latest sick letter to be penned by the sex pest in a playground off Essex Road, Shepway, on Sunday, April 14. It contained the same vile content as the others. The letter was found just a short walk away from where another obscene note turned up in December.

Two 14-year-old girls found a letter in an alleyway between Middlesex Road and Sutton Road on December 7. The writer threatened to sexually assault any woman who read it.

The police spokeswoman added: "The latest letter is the same as the others that have been found. It has been written by the same person and contains the same obscene material."

Anyone who has any information that can help police inquiries, or who knows the witness being sought, is asked to contact Sgt Andy Francis on 01622 608182 or the confidential Crimestoppers line on 0800 555 111.