A senior police officer who leaked details about the phone hacking inquiry to the News of the World has been jailed for 15 months.

Det Ch Insp April Casburn, 53, told the newspaper that six people were being questioned in relation to phone hacking, and also claimed some of her colleagues were more interested in meeting celebrities than bringing hackers to justice.

Casburn, who headed the National Terrorist Financial Investigation Unit, was jailed at the Old Bailey after the jury heard she "sought to undermine a highly sensitive and high-profile investigation at the point of its launch."

The court heard that Casburn contacted NoW reporter Tim Wood and offered details of the phone hacking inquiry in September 2010, just days after the investigation reopened.

Casburn told Wood that some of her colleagues treated the probe as a "jolly", and said there was "palpable excitement" at potential celebrity encounters among officers conducting the inquiry.

Although it was alleged that Casburn demanded money in exchange for the information, the defendant denied this allegation. She claimed she was instead acting in the public interest, out of concern that resources were being diverted from more pressing counter-terrorism work.

Casburn was found guilty two weeks ago and given a jail sentence this morning (1 February), even though she has recently adopted a child.

Speaking after the verdict, Det Ch Sup Gordon Briggs, who is overseeing the inquiries into phone hacking, corrupt payments and other privacy breaches, rejected the idea that the Casburn should be treated as a whistleblower.

"There may be occasions when putting certain information in the public domain, so-called whistleblowing, may be tolerated. This is not one of them.

"It's totally unacceptable for a serving police officer to leak confidential information to journalists for private gain. In doing so they let down the public and they let down their hard-working, honest colleagues.

"To act in that way is a gross breach of public trust."