Matt Nixson was sacked after News Corp claimed to have found email exchanges that implicated him in wrongdoing

Matt Nixson, former features executive of the Sun and News of the World, has been accused of bribing a prison guard for information about the Soham killer Ian Huntley.

Nixson sanctioned a ?750 payment to a prison guard while working for the News of the World in March 2009, according to court documents filed by his former employer on Thursday.

Nixson is suing his former employer for wrongful dismissal and breach of contract and the claims were made by News Group Newspapers as part of their defence. Nixson, who joined the Sun in April 2010 after five years at the NoW, has consistently denied any wrongdoing.

News Group Newspapers, publisher of the Sun and NoW, claimed in the court filings that it had unearthed emails to show that Nixson told a reporter to handle the payment "very carefully" because the company had a "forensic new accountant who doesn't brook any funny business".

In a follow-up email, Nixson is alleged to have said: "We'll have to pay ?750 then chuck her some more money later".

Nixson was sacked by the Sun in July last year after parent company News Corp said it unearthed emails that implicated him in wrongdoing.

In a statement, a solicitor for Nixson said he "neither bribed nor ever admitted to bribing a prison officer".

News Corp's management and standards committee investigating phone hacking recommended that Nixson be immediately dismissed after it claimed it had uncovered evidence of wrongdoing.

The court filing included an email exchange it claimed was between Nixson and another NoW reporter, Matthew Acton, in which Nixson was allegedly told: "That Huntley prison officer is down for a grand on that tale. Had to give her a contract but reckon she'll get other stuff."

According to the filing, Nixson replied: "Thought it was practically a freebie. We'll have to pay ?750 then chuck her some more money later."

News Corp said it should be inferred that Nixson "was aware of, and had given his approval for, journalists on the News of the World to engage in unlawful interception of voicemail messages and/or blagging."

News Corp claimed Nixson was told in a separate email in November 2005: "I'll get [redacted] to do his thing on [redacted's] phone".

A solicitor for Nixson said in a statement late on Thursday: "Contrary to reports based on defences raised by the defendants for the first time some six months after summarily dismissing him, my client wishes to make it absolutely clear that he neither bribed nor ever admitted to bribing a prison officer.

"My client will continue to vigorously pursue his well-founded claims against NGN Ltd, Lord Grabiner QC [chairman of News Corp's management and standards committee] and others, up to trial if necessary and is confident of success."