Image caption Counter-terrorism officer April Casburn was found guilty of misconduct in public office

The first person to be prosecuted as part of the investigation into payments by journalists to officials has been jailed for 15 months.

Det Ch Insp April Casburn, 53, from Essex, was convicted last month of misconduct in public office.

She had offered to sell information to the News of the World newspaper after the inquiry into hacking by the tabloid reopened in 2010.

The sentencing judge called it "a corrupt attempt to make money".

The Metropolitan Police said it was "a great disappointment that a detective chief inspector in the counter terrorism command should have abused her position in this way".

Casburn had said she contacted the paper out of public interest, but Mr Justice Fulford said her offence could not be described as whistle-blowing.

She spoke to journalist Tim Wood about the fresh investigation into phone hacking and claimed she did so because she was concerned about counter-terror resources being wasted on the phone-hacking inquiry, which her colleagues saw as "a bit of a jolly".

Analysis April Casburn goes to prison as the first person convicted as part of Operation Elveden. During mitigation, her barrister argued that the exceptional nature of her offence - one 'mad telephone call' - should not lead to a precedent-setting sentence which would affect any future convictions relating to corrupt relationships between police and journalists. But Mr Justice Fulford made clear she had no excuse for her actions - it was a straightforward and troubling case of corruption. This was the key factor. He assessed that her actions had damaged the public's trust in the police and potentially damaged the integrity of a new investigation. There was, in his view, no defence of whistle-blowing - of speaking out in the public interest. And that's why he concluded that the public interest would be in jailing the disgraced detective.

The detective denied asking for money, but Wood had made a note that she "wanted to sell inside information".

The newspaper did not print a story after the call and no money changed hands.

The judge, in his sentencing remarks at the Old Bailey said Wood was "a reliable, honest and disinterested witness" who had "absolutely no reason to lie".

"If the News of the World had accepted her offer, it's clear, in my view, that Ms Casburn would have taken the money and, as a result, she posed a significant threat to the integrity of this important police investigation," he said.

He told her it was "a corrupt attempt to make money out of sensitive and potentially very damaging information".

Mr Justice Fulford went on: "Activity of this kind is deeply damaging to the administration of criminal justice in this country. It corrodes the public's faith in the police force, it can lead to the acquittal or the failure by the authorities to prosecute individuals who have committed offences whether they are serious or otherwise."

Casburn, who was found guilty after a trial at Southwark Crown Court, is in the process of adopting a child, and the judge said had that not been the case she would have been sentenced to three years.

The judge said he was particularly concerned about the child, and admitted that her absence while she is in prison could be damaging.

However, he said that, had she not been arrested, the detective would have returned to work by now, and therefore the child would be cared for by others anyway.

Image caption The phone-hacking scandal led to the closure of the News of the World

The Sunday tabloid was closed down in 2011 amid outrage over its hacking into voicemails.

'Unhappy at work'

The offence happened in September 2010 when Casburn, from Hatfield Peverel, was managing the national terrorist financial investigation unit.

Ahead of sentencing, Casburn's defence team told the judge her only offence was "being very unhappy at work and making a mad telephone call" to the News of the World.

In a statement, the Metropolitan Police said: "We hope that the 15-month prison sentence handed down to this officer sends a strong message that the leaking of confidential information for personal gain is absolutely unacceptable and will not be tolerated."

It said she had "betrayed the service and let down her colleagues", adding that there was "no place for corrupt officers or staff" in its police force.

Casburn, who will now face Met Police disciplinary proceedings, was accused of a separate charge under the Official Secrets Act but the prosecution offered no evidence.

Her arrest was one of 59 that have been made as part of the ongoing Operation Elveden investigation.

Operation Elveden is running alongside the Operation Weeting inquiry into phone hacking, and Operation Tuleta into allegations that computers were hacked to obtain private information.

Confidential sources

Meanwhile, the journalist who took Casburn's call has said he gave evidence in the trial after taking advice from a union representative "only to confirm" that he had written an e-mail to superiors outlining the conversation.

In an article published on the ExaroNews website, Wood said he would always protect the source of a story. He added that he felt "sympathy for Casburn, who I believe was sacrificed by big business".

Evidence in the trial was provided to police by the management standards committee set up by the News of the World's owner, the Met Police said.

"The [committee] was established to counter damaging claims of a cover-up... over phone hacking," Wood said.

"But I believe that it has gone too far, betraying more confidential sources than any other body or person in the history of journalism."