Virgin Atlantic has admitted that one of its staff members leaked the flight details of more than sixty celebrities to the Big Picture paparazzi agency – but insisted it was an "isolated incident".
The company launched an internal investigation in April after Press Gazette and The Guardian obtained emails that appeared to show one its employees was handing over the flight details to a senior figure at Big Pictures.
Celebrities named in the cache included the likes of Madonna, footballers Ashley Cole and Jermain Defoe, actresses Sienna Miller, Scarlett Johansson and Gwyneth Paltrow, and pop stars Nicole Scherzinger, Robbie Williams and Cheryl Cole.
The Information Commissioner's Office (ICO) confirmed it was investigating the allegations.
A spokesman for Virgin Atlantic said: "Following the allegations in the press in April, we voluntarily contacted the Information Commissioner's Office and have fully assisted with their enquiries," a spokesman for Virgin Atlantic said.
"Our internal investigation found no evidence that this was anything other than an isolated incident relating to a single member of staff who is no longer with the business. We continue to treat the security of customer information extremely seriously and apologise to the passengers affected."
The ICO said: 'We are currently making enquiries to establish the precise nature of the alleged incident before deciding what action, if any, needs to be taken."
When first confronted with the evidence Virgin suggested the email chain could be unreliable and that the employee suspected of the leaks denied the allegations, claiming she was the victim of identity theft.
It is understood that she later resigned the company in the wake of the allegations.