A high-ranking British detective has been charged with offering to brief the News of the World about the progress of a police investigation into phone hacking at the now-defunct tabloid — one of the most serious allegations so far uncovered in the wide-ranging scandal.

Scotland Yard Chief Insp. April Casburn has been charged with misconduct in public office for allegedly giving the Rupert Murdoch-owned News of The World newspaper information in September 2010. (Kirsty Wigglesworth/Associated Press)

The charge sheet, made public Monday at London's Westminster Magistrates' Court, alleges that senior counter-terrorism investigator April Casburn offered to keep the News of the World up to date on whether police would reopen their investigation into wrongdoing at the Rupert Murdoch-owned tabloid.

If proven, that effectively would mean that the scandal's chief suspects were being offered the inside track from the police force that would eventually arrest them.

Casburn, 53, spoke only to confirm her name, address, and date of birth at Monday's hearing. She has yet to enter a plea to a charge of violating the Official Secrets Act, and was released on bail until her next hearing, due on Nov. 2.

Casburn was formerly the head of Scotland Yard's terrorist financing investigation unit. The initial investigation was handled by anti-terror police because it involved phone hacking of the Royal Family.

The charges laid against her follow a year of revelations about how decisions taken by senior police officials helped keep the phone hacking scandal under wraps.

When it finally erupted in July 2011, the revelations that journalists at the News of the World systematically broke the law to win scoops sent shockwaves across the British political establishment.

Murdoch was forced to close the paper, police arrested dozens of journalists and Prime Minister David Cameron's press aide was forced to resign. Three top police officials — including London's most senior police officer — also stepped down.

Police have since pledged to rebalance their relationship with the press.