A member of staff at London's Metropolitan Police (MPS) headquarters was one of two people arrested on Tuesday as part of a bribery investigation sparked by the phone-hacking scandal at the News of the World tabloid.

The 55-year-old man, and a 48-year-old woman, were arrested "for suspected conspiracy to cause misconduct in public office," police said in a statement.

They were held at their home in Berkshire, west of London, and were being questioned at separate police stations in the capital, the statement said.

A total of 74 people have now been arrested under Operation Elveden, the investigation into illegal payments to police and public officials by journalists.

The probe was launched following the scandal at media baron Rupert Murdoch's News of the World, which he shut down in July 2011 after it was revealed to have hacked the phones of hundreds of high-profile figures.

Former Murdoch aide Rebekah Brooks and Andy Coulson, a former News of the World editor and Prime Minister David Cameron's ex-communications chief, go on trial next month on charges of phone-hacking and alleged bribery. They both deny the charges.