A BT engineer is believed to have jumped to his death from close to his workplace on the fourth floor of a town centre building.

Stephen Ainslie, 44, of Darwen, had worked at the Jubilee Street BT site in Blackburn for 20 years. His body was found on land near to the company's telephone exchange car park at 10.30am on Friday.

It was initially thought he had been on the roof before his death but a BT spokesman confirmed he had been seen close to where he worked just before the incident and it would be incorrect to say he had been on the roof.

Police are still investigating the circumstances, along with Blackburn coroner Michael Singleton. A Health and Safety spokesman said the death was being treated as a potential suicide.

Mr Ainslie was an engineering planner who worked to maintain the telephone network. Tony Martin, chairman of the mid-Lancashire branch of Communication and Workers Union, of which Mr Ainslie was a member, said: "It is a personal tragedy for all his family.

"His wife must be distraught. We will be writing to her to offer her our support."

Police say they are unable to state at what time or from where on the building Mr Ainslie fell.

Det Sgt Simon Giles, of Blackburn CID, who is leading the investigation, said there were no suspicious circumstances surrounding the death but there had been no witnesses.

He said: "At 10.30am on Friday morning a male body was found on land adjacent to the car park of the BT building.

"Police investigations are under way in conjunction with the coroner. There are no suspicious circumstances but we are investigating and interviewing to try to establish the chain of events which led to the fall."

Mr Ainslie's father, William Ainslie, of Bonsall Street, Blackburn, was in Spain when he heard the news. He said he did not know how his son had died.

"We are still in the dark as to what happened, it is just such a shock. We were a very close family," he said.

Mr Ainslie leaves a wife.

A Health and Safety Executive spokesman said they were aware of the incident but they were not involved in it on a practical basis as yet as it was being treated as a potential suicide.