Update 27 July 2011 – Now found safe and well
Mr Hornabrook last made contact with a family member on Friday 22 July, saying he was going to stay with a friend in Monmouthshire.
His family contacted police on Sunday afternoon after they had contact from another friend of Mr Hornabrook who had received a message from him, indicating that he intended to harm himself.
Further police enquiries led officers to believe that Mr Hornabrook is in the in the Leeds area.
Mr Hornabrook is described as white, 6ft 2in tall and of slim build. He has collar length light brown hair which is greying at the sides and blue eyes.
He was last seen wearing a dark brown three-quarter length coat, dark trousers and may be carrying a brown overnight bag.
Officers are appealing for anyone who may have seen Mr Hornabrook over the past few days, or know of his current whereabouts, to contact them.
PC Ian Wilkinson, who is investigating his disappearance, said: “We have grave concerns for Mr Hornabrook’s safety and welfare. He has recently suffered a family bereavement and we know from our enquiries that he is currently in a very distressed frame of mind.
“It is very important that anyone who has seen him over the last few days, or knows where he is now, gets in touch immediately.
“Better still, if David reads or hears this appeal, I ask him to please get in touch with the police, family or friends and let us know you are safe.”