A spokesman for Virgin Atlantic said: "The investigation identified that a number of alarms were triggered in flight, in response to which our flight crew took positive action in line with procedures by returning to Gatwick and completing an evacuation of the aircraft.
“The flight crew and cabin crew followed safety procedures at all times and carried out their duties in a professional manner to ensure the safety of our passengers was maintained throughout the flight and during the evacuation."
Privacy lawyer Gerald Shamash has told the Guardian that the allegations a Virgin Atlantic employee passed on information about eight celebrities is "extremely worrying" and "this could be the tip of the iceberg".
Mr Shamash also said advance knowledge of the whereabouts of celebrities was the "bread and butter" of life as a picture agency or tabloid newspaper.
"Once it has these details, the agency does one or two things: it keeps [the information] to sell it or phones a newspaper to say this person has gone to Los Angeles. It's a symbiotic relationship with newspapers."
Reacting to the allegations that an employee at Virgin Atlantic passed the flight details of eight celebrities including the footballer Jermaine Defoe to a paparazzi agency, a spokeswoman for the footballer said:
"This is a serious breach of privacy. We'll be consulting with our lawyers and investigating the matter further."
Virgin Atlantic said they are "deeply concerned" by reports that eight celebrities flight details may have been passed on to a paparazzi agency by a former employee.
The allegations that have been raised are extremely serious and we have launched an immediate investigation.
The security of customer information is our highest priority and we have robust processes in place to ensure that passenger information is protected. The incident that has been alleged concerns eight customers’ flights booked in 2010 and we are in contact with all of those people.
It is too early to draw conclusions on this matter but of course we would deeply regret any concern that these allegations may cause the individuals involved.”