A love-sick man killed himself with a rifle after being shunned by the woman he adored on her doorstep.

The 36-year-old shot himself in a courtyard outside a home in Southover High Street in Lewes.

He was taken to hospital but was pronounced dead on arrival.

The man, believed to be from the Bristol area, had been seen by neighbours behaving strangely earlier in the day just 50 yards from the historic Anne of Cleves house.

A woman from the property called the police to report an intruder just after 7pm on Tuesday.

Two unarmed police officers and two community support officers attended and when one police officer opened the front gate to investigate the man, stood in front of the house, picked up a rifle and pulled the trigger.

A police source said: "He thinks there's a relationship, she doesn't agree - that's basically it.

"One officer realised there was a man in the yard and as he pushed open the door the man picked up a rifle and a shot was fired."

A Sussex Police spokesman said: "Officers attempted to administer first aid until the ambulance arrived but the man died at hospital.

"No-one else is being sought in connection with the incident but we are continuing to investigate it for the coroner."

The policeman was the only witness to the suicide and is being supported by one of the force's welfare officers.

The Independent Police Complaints Commission - the national police watchdog - has been brought in to investigate because of the police officer's presence at the death.

Detective Inspector Martin Sapwell, who is in charge of the investigation, said: "We believe there's an association between the man and someone at this address."

The annex property is rented from the main Georgian house by a single woman who had left the house and was being spoken to by police liaison officers.

Neighbour Rebecca Lumsden said she saw a man with short blonde hair or a bald head acting oddly earlier in the day.

She said: "There was somebody chucking stuff that looked like board games over the wall while standing on a small black chair outside his car.

"I thought it was a bit weird."

Wilfrid Charles, 39, who was working from home nearby, said: "I heard the bang. It just sounded like a door slamming."

Another neighbour, Nikki Gower, 42, said: "I saw the little chair and thought it was strange.

"This is not the sort of thing that normally happens in sleepy Southover High Street."

Police are appealing for witnesses who saw any suspicious activity in the street to call them on 0845 6070999 quoting Operation Friary.