London, November 22 : A police helicopter nearly collided with a UFO over Birmingham, says a report.
The incident is detailed in a document compiled by experts from the Airprox Board, which records near misses and reports them to the military and air traffic control units.
The reports suggests that the pilot managed to swerve out of the mystery aircraft's way while he was on a routine police surveillance task over the city centre earlier this year.
There were also two police observers on board the helicopter when the incident occurred in May.
All three reported seeing a strange aircraft with two continuous blue/green lights, said the report.
"The front observer saw unidentified lights flying around their aircraft. The pilot established visual contact, as he manoeuvred the aircraft to avoid a collision and to identify the light source," the Telegraph quoted the report as stating.
The documents said that the mysterious object was about 100m away from the helicopter, and that it flew around it.
The pilot said that he initially thought that the object was a radio controlled aircraft and that it was purposefully flown around the helicopter.
"He (the pilot) believes the lights may have come from a radio controlled fixed wing aircraft, the lights being to assist with night flying," the report said.
Even upon searching the area with the aid of a thermal camera, the pilot could not locate any signs of radio-controlled model activity.
The British Model Flying Association ruled out the possibility, insisting that the mystery object was flying too high to be a miniature craft.
"A helicopter was nearly blown out of the sky. This is a very disturbing incident which needs to be thoroughly investigated by the MoD and the Civil Aviation Authority as well as other near misses," said Nick Pope, who previously worked for the Ministry of Defence's UFO desk.
"The conclusion on the report is unsatisfactory especially when this aircraft came within seconds of a collision.
"It is a very interesting case especially when you look at the eyewitnesses. They are credible and reliable sources who have experience in night time flying.
"This sighting clearly illustrates that whatever one believes about UFOs, this incident raises important air safety issues and should be taken seriously," Pope added.