A prison officer accused of selling stories to The Sun told jurors that if he had been in it for the money he could have sold celebrity "tittle tattle" about snooker world champion Ronnie O'Sullivan's jailed father.
Lee Brockhouse insisted he only highlighted issues in the public interest which is why he never took the opportunity to peddle stories about high profile inmates at HMP Swaleside in Kent.
That also included So Solid Crew band member Carl Morgan, who was serving a life sentence for shooting a man, and teacher Philip Lawrence's killer Learco Chindamo, the court heard.
The 44-year-old is on trial at the Old Bailey accused of misconduct in a public office. Alongside him is Sun journalist Nick Parker who is charged with aiding and abetting him.
Giving evidence in his defence, Brockhouse said: "Ronnie O'Sullivan's father was in prison at Swaleside. He was give a life sentence for murder."
His lawyer Adam Wiseman queried whether he ever tried to "peddle that sort of tittle tattle", the defendant said: "No. I was his personal officer – anything to do with them, whether it be inside or outside, they would come to you first and foremost."
Asked why not, Brockhouse replied: "Because it was not in the public interest. It is not showing a broader view of what is going on at the jail. It's concentrating on that one person – it's not an illegal way of how drugs are coming in or mobile phones coming in."
Brockhouse told the court that Parker was his contact at The Sun but he also gave information to a reporter at The People too.
On being paid in cash, he said: "All I saw it as Nick's appreciation for helping him do his job to highlight the problems of what is going on in this country's prison service."
He said he asked Parker not to name him as the source because he did not want the "focus" to be deflected from the story itself.
Brockhouse said when he dealt with The People he was not trying to start some sort of competition for the stories he had to offer.
"I was not in the process of playing one off against the other. I did not ring Nick Parker and say 'how much am I going to get for it?' and then ring The People," he said.
He highlighted a story about a member of prison staff having a relationship with an inmate as a story that was in the public interest.
"Unfortunately within the prison service this is not the first instance of an officer having a relationship with a prisoner whether it is female or male.
"What she has done here is a total disregard for her safety and fellow officers' safety. She is open to assault, attack sexually physically if other offenders found out what was going on."
The court heard that Brockhouse stopped his contact with all newspapers nearly two years before his arrest.
Mr Wiseman asked him why he did not carry on, and the defendant replied: "Because of what I had done – for me it had served its purpose and the main purpose was to show people outside the system what was going on inside the jails. I could have sold other stories about other celebrities."
Parker, 53, of Twickenham, south-west London, denies three counts of aiding and abetting misconduct in public office, a count of handling stolen goods, and one of securing unauthorised access to computer material.
Brockhouse, of Sittingbourne, Kent, denies two counts of misconduct in public office, and Michael Ankers, 30, of no fixed abode, denies a count of theft, and handling stolen goods, relating to the mobile phone.