DETECTIVES have questioned a 45-year-old man who claims to be "Soldier David" - the man behind a string of threatening letters and malicious calls.

But police said last night that the investigation into the letters was still going on.

For two years, staff at stores and supermarkets in Thornaby, Teesside, have had to put up with a torrent of abuse from a mystery man with an irrational hatred of children.

His letters have threatened to murder shop staff for selling fireworks and even carry out another Dunblane-style massacre.

Earlier this week, he threatened to break the legs of a male employee at one of the town's Bells Stores only hours after an appeal to find him had been launched.

Following a number of press and radio appeals to catch the culprit, a man gave himself up at Thornaby police station on Wednesday, claiming to be behind the letters and phone calls.

After an initial interview he was not held by police, but inquiries are continuing.

A spokeswoman for Cleveland Police said: "Police recovered a number of items from his home address in Thornaby and these will now be sent for forensic examination.

"Police inquiries are continuing."

The public are being asked to still get in touch with police if they have any information.

They can contact Thornaby police on (01642) 302816 or Crimestoppers on 0800 555111.