Two passenger jets came so close to crashing at Heathrow last month that the organisation which normally investigates accidents is looking at the incident.

The two aircraft involved were a British Airways Boeing 747 from Japan and a British Midland Airbus 321 taking off for Brussels.

Sources in the industry and safety regulation are saying the planes came within one hundred feet of colliding.

According to industry sources the 747 was attempting to land on a runway being used by the Airbus to take-off.

It was foggy at Heathrow and it is believed controllers were under pressure to land aircraft more rapidly in order to reduce delays.

The controller at Heathrow was a trainee being overseen by a mentor.

When it was realised the two aircraft were on a collision course, the landing was aborted but its thought they came closer than one hundred feet.

The government have confirmed that the Air Accidents Investigation Branch (AAIB) are preparing a thorough report into this incident.

Normally near-misses are the responsibility of the UK airprox board - a part of the Civil Aviation Authority.

Only very serious cases are handled by the AAIB

The independent Aviation Study Group have written to the government to express their concerns over the incident.