A 12-year-old boy who was killed when a car driven by his older brother collided with a police car has been named.

Oscar Orpen, 12, was in the front passenger seat of a red Peugeot 106 driven by 18-year-old George Orpen when the crash happened.

The boys' parents were last night too upset to talk and George remains in hospital with a broken pelvis.

Neighbours near the family's detached country home in Staplefield Road, Cuckfield, were also too distressed to comment on the incident, which happened just a few miles away at Staplefield, near Haywards Heath, shortly after 4pm on Friday.

An investigation has been launched and Sussex Police have voluntarily reported the incident to the Police Complaints Authority, which is overseeing their inquiry.

Authority spokesman Mike Delaney said: "The investigation will be carried out by Sussex Police but we will be supervising.

"It is really to ensure a thoroughly impartial investigation is carried out but we won't be taking over.

"It will take some weeks if not months to finalise. Once we have received a report, we will then see what action, if any, needs to be taken.

"We don't set a time limit on these things because there are people who need to be interviewed and the lad who was driving is still in hospital and will probably need some time."

The Peugeot 106 and police car had been travelling in opposite directions when they crashed on the brow of Hammer Hill, on the B2114 at Staplefield.

Oscar died at the scene and his brother was cut free by firefighters and taken to the Princess Royal Hospital in Haywards Heath.

The two officers in the Toyota Avensis police car, who had been travelling north to Crawley police station where they were based, were taken to hospital with minor injuries.

Police say the driver, a constable in his 40s, and his passenger, a constable in his 30s, were released later the same day and are on sick leave.

They had not been in a chase or answering a 999 call.

Two police signs asking for witnesses to the crash, some scattered sand and a piece of burnt grass verge were all that remained at the crash scene last night.

Residents in the area said the road was not known as an accident black spot but could be dangerous if motorists did not know it well or drove too fast.

Chief Superintendent John Dransfield, divisional commander for North Downs division, which includes Crawley and Staplefield, said: "We wish to express our sympathy to the family and friends of the boy who has died.

"We are supporting all of those who were involved in the crash and a road policing department family liaison officer has been with the boy's family."

Police are appealing for witnesses to call them on 0845 6070999.