A woman was seen weeping at a beauty spot shortly before a teddy bear with a mysterious note pinned to it was found stuffed into railings.

A dog walker saw the woman being comforted by a man in the car park at the Broken Scar picnic site in Darlington on Sunday. A teddy bear was lying on the floor next to them.

The witness contacted police after reading the story of the note and the six-hour manhunt which followed its discovery in The Northern Echo yesterday.

Part of the letter reads: "Daddy and Mummy love you always and forever. You are and will always be in our hearts forever. Hope you understand why we did what we did."

Inspector Brian Maudling, of Darlington police, said the man was walking his dog at about 10.45am when he noticed them.

"The woman was distressed and crying and the man was trying to comfort her," he said. "They were there for at least ten to 15 minutes."

The letter was initially treated as a suicide note but detectives also thought it may have been written by parents to a child they had given away.

"We're continuing to keep an open mind on exactly what the motive was for the bear and the note," said Insp Maudling. "What we need is to speak to the couple urgently so we can clear up the mystery and draw a line under the police operation."

The couple were both aged between 30 and 35. The woman was about 5ft 6in tall and of average build. She had shoulder length dark hair and was wearing dark clothing.

The man was about 5ft 8in tall and had dark hair which was brushed over the collar of his black leather coat.

There were two vehicles in the Broken Scar car park at the time - a jewel-grey, 2.8 turbo diesel Mitsubishi Shogun, believed to have been the couple's, and a white Citroen C5.

Police also want to speak to the driver of the Citroen C5. They can be contacted on (01325) 742134.

* Detectives have ruled out a link between the note and the stillborn baby found buried in a garden in Grange Road, Darlington, last month.

The Crown Prosecution Service said yesterday that the mother of the dead baby, who came forward to police, would not be prosecuted.