Detectives are unlikely to catch the operator of a drone which is believed to have hit a British Airways plane because there is no registration system for users in the UK, an expert has claimed.
The pilot of flight BA727 from Geneva in Switzerland reported being hit as the Airbus A320 approached Heathrow Airport on Sunday afternoon with 132 passengers and five crew on board.
Scotland Yard said aviation police based at the airport are investigating but no one has been arrested.
The Air Accidents Investigation Branch has also begun an investigation.
Justin Pringle, chief technology officer at Newcastle-based firm Drone Operations, told the Press Association: "There isn't any chance of catching the pilot because drones do not have to be registered.
"It's an untraceable event. There doesn't have to be any registration on the drone, there's nothing that tells you where you got it from and ultimately someone has got one of these things and abused it."
Transport Minister Robert Goodwill said the Government is looking at the possibility of introducing a registration scheme in the UK, similar to the ones already in place in Ireland and the US.
Mr Pringle warned that anyone can walk into a shop, hand over £1,000 and walk out with a drone.
"At no point have you had a conversation about safety or the rules and regulations attached to that vehicle," he added.
The collision is the latest and most serious in a string of incidents involving drones at Heathrow, with several near misses between flights and unmanned aircraft reported in the last year.
And it raises the issue of regulation and control of drones, especially in sensitive areas like airports.
BA said the aircraft landed safely and was examined by engineers before being cleared to take off for its next flight.
Steve Landells, flight safety specialist at the British Airline Pilots Association (Balpa), called for greater enforcement and awareness of rules that govern drone flights.
He said: "Frankly it was only a matter of time before we had a drone strike given the huge numbers being flown around by amateurs who don't understand the risks and the rules."
The Civil Aviation Authority advises that drone operators must be able to see the craft at all times, must not fly it above 400ft and that drones fitted with cameras must not be flown within 50 metres of people, vehicles or buildings, or over congested areas or large gatherings such as concerts and sports events.
Assistant Chief Constable Steve Barry, who is national lead on drones for the National Police Chiefs' Council, believes many drone owners are not aware of the laws controlling the devices.
He said: "In the vast majority of cases people are ignorant of the rules. We want people to understand what the regulations say. There is a social responsibility to not hurt people."
The senior officer added: "As a lay person I'd say there's more risk at the moment from drones coming into contact with people on the ground rather than aircraft. These drones, if they land on people's heads, would cause them a lot of harm."
A report in March by the UK Airprox Board (UKAB) found there were 23 near misses between drones and aircraft in the six months between April and October last year, including two at Heathrow.
On September 22 a Boeing 777 that had just taken off reported a drone narrowly passed down its right hand side. Investigators concluded the drone was at the same height and within 25 metres of the jet. A report was made to police but the drone operator was not traced.
Days later, on September 30, a drone was flown within a similar distance of an Airbus A319 landing at Heathrow. The jet was flying at an altitude of 500 feet and was on the final approach to the west London airport when the drone was spotted.
A CAA spokesman said it was "totally unacceptable" to fly drones close to airports and anyone flouting the rules can face severe penalties including imprisonment.
A Scotland Yard spokeswoman said a pilot on an inbound flight into Heathrow Airport from Geneva "reported to police that he believed a drone had struck the aircraft" at around 12.50pm.
On investigation it transpired an object, "believed to be a drone", had struck the front of the aircraft.