A plane crash which killed a young girl and her father may have been caused by a passenger leaning on flight controls.

Lauren Bevan, 11, and her father Peter, 43, from Cranham Avenue, Billingshurst, died during a pleasure trip in December 2000.

A report into the tragedy, which also killed Mr Bevan's brother Roger, 48, from Bristol, and pilot Alistair O'Byrne, 29, was released yesterday after a lengthy investigation.

The cause remains inconclusive but it is thought one of the passengers may have accidentally leaned on the dual controls which caused massive strain on the left wing, causing it to snap off.

This was compounded by the pilot's natural reaction to regain control of the Piper Cherokee Arrow II, which caused more strain on the structure, and the craft went into a spinning dive.

The Air Accident Investigation Bureau (AAIB) report concluded: "A manoeuvre, resulting from unintentional and unusual control inputs by either the pilot and/or the front seat passenger, sufficient to overload the wing structure, was the most likely cause of the wing failure.

"The manoeuvre being unintentionally initiated by, possibly, the front right seat occupant grasping the control yoke for support and completed by the pilot in an attempt to recover the aircraft, could not be dismissed."

Mr O'Byrne, from Surrey, a friend and work colleague of Peter Bevan at Heathrow airport, had flown the party from Thruxton airport in Hampshire, when the crash happened.

They had been due to enjoy a flight over Hampshire, Berkshire and Oxfordshire countryside.

The 26-year-old plane disintegrated after the left wing fell off over a field in Lambourn, Berkshire, and crashed vertically through trees before hitting the ground.

No mechanical faults were found on the wing or controls and there were no adverse weather conditions.

As a result of the AAIB inquiry, a safety recommendation had been issued stating that the Civil Aviation Authority should review current training for private pilots and should make more literature available about the effects of stress on aircraft when making manoeuvres at low speeds.

The report stated: "While apparently flying normally in clear air at a height of about 4,200ft at or below manoeuvre speed, the aircraft suffered an in-flight structural failure."

Referring to eyewitness accounts, the report said that they were all generally consistent.

It read: "The aircraft deviated from a normal flight path and was seen to be rolling and pitching while descending.

"This was also described as 'spinning' or 'doing aerobatics' and the engine/ propeller noise was heard to increase and then stop.

"Pieces of structure were seen to fall from the aircraft and about a third of the left wing was seen to be missing.

"This accident does highlight the fact that flying at or below manoeuvre speed does not provide protection of the aircraft from damaging stresses for all possible manoeuvres."

Highlighting its safety recommendation, the AAIB said: "The CAA should review the current training syllabus for the Private Pilot's Licence and the literature available to pilots generally with respect to raising awareness of the significance of manoeuvre speed.

"It should make it clearly known that flying at or below manoeuvre speed does not provide protection for the airport structure from damaging stresses for all possible combinations and reversals of control inputs."

Lauren had been a pupil at St Francis of Assisi RC School in Crawley before the family moved from Horsham to Billingshurst.

She then attended The Weald School in Billingshurst and was a member of Young Billingshurst Dramatic Society.