A senior detective from Essex committed a "gross breach" of the public's trust by trying to sell information to the News of the World about a phone hacking investigation, jurors were told today.

Detective Chief Inspector April Casburn, 53, is accused of offering the now-defunct tabloid information about Operation Varec, the investigation into whether Scotland Yard's inquiry into phone hacking should be reopened.

She is accused of one count of misconduct in public office on September 11, 2010, which she denies.

At that time she was working in counter terrorism, managing the National Terrorist Financial Investigation Unit.

Today Southwark Crown Court was told that one of her team had been asked to carry out financial investigations as part of the Scotland Yard probe into phone hacking.

It is alleged that she rang the news desk of the tabloid at 7.51am that Saturday morning to offer information in exchange for payment.

The court was told that she gave the names of two of the people under investigation during the conversation.

Prosecutor Mark Bryant-Heron said: "The prosecution says she sought to undermine a highly sensitive and high profile investigation at the point of its launch.

"The prosecution say, and it's a matter for you 12, that the act of telephoning the News of the World to offer to sell information and the provision of some information during that call was misconduct, it was misconduct in public office.

"It was a gross breach of the trust that the public places in a police officer not to disclose information on a current investigation in an unauthorised way, or to offer to do so in the future for payment."

The newspaper did not publish anything and no payment changed hands, the court heard.

Casburn, from Hatfield Peverel, admits making the phone call but denies asking for money, and says she had reasonable excuse.

She says she was concerned that resources that were supposed to be used to combat terrorism were being allocated to the phone hacking investigation, and that much of the information was already public knowledge.

The court heard that the call was taken by a journalist called Tim Wood, who was then a news editor for the NotW.

He said the caller refused to give her name, but introduced herself as a senior police officer.

Mr Wood told the jury: "The one thing that stands out in my mind is the fact that she kept going on about Lord Prescott. Her saying that he was pressing for them to put charges on the News of the World, and she was saying that she felt it was wrong that he was interfering in the scandal, so to speak, and she resented that."

He added: "She was almost justifying her call by saying that it was this interference by Prescott that had upset her."

Mr Wood sent an email to news editor Ian Edmondson and crime journalist Lucy Panton after the call to say that a police officer wanted "to sell inside information" on the phone-hacking inquiry.

Casburn told him that six people were under investigation including former NotW editor Andy Coulson and reporter Sean Hoare, Mr Wood said.

She also mentioned that "counter-terrorism assets" were being used in the probe, which was "highly unusual".

The trial continues.