A Virgin Atlantic employee has resigned following allegations she routinely fed information about the airline’s celebrity clientele — from Madonna to Sienna Miller — to a paparazzi agency.

The employee was a junior member of the team that looks after high-profile clients, Virgin said Friday. She quit Thursday before reports published in the Guardian and the Press Gazette alleged that she had passed the booking information of more than 60 celebrities on to the Big Pictures photo agency.

Among those allegedly targeted: Britain’s Princess Beatrice; singers Madonna and Rihanna; actors Charlize Theron, Kate Winslet, Daniel Radcliffe and Miller; comedians Sacha Baron Cohen and Russell Brand; and a slew of U.K. celebrities and sports figures.

The Guardian and the Press Gazette cited messages allegedly sent by the employee to someone at Big Pictures Ltd. as the basis for their stories.

The Associated Press had no immediate way of verifying the authenticity of the messages, but the Guardian said it had carried out checks confirming that at least some of the celebrities had traveled to the destinations mentioned in the emails.

Calls and emails to representatives of around a dozen of the celebrities mentioned went unreturned Friday, a public holiday in Britain. A representative for Princess Beatrice declined comment, while Kate Winslet’s publicist, Heidi Slan, said the star wasn’t reachable.

In a statement, Virgin Atlantic Airways Ltd. called the allegations “extremely serious’’ and said it had launched an investigation. The airline, which is majority-owned by billionaire adventurer Richard Branson, confirmed that high-profile clients were involved but declined to comment on the British newspapers’ figures.