A Sun reporter from Brockley has been cleared of plotting with a Government press officer to illegally leak a string of stories, including secrets of Alistair Darling's 2010 budget.

Clodagh Hartley was accused of paying Her Majesty's Revenue and Customs (HMRC) press officer Jonathan Hall around £17,000 for the tips over a period of three years.

The court heard she suggested to Hall that he channel the News International payments through the bank account of his girlfriend Marta Bukarewicz because he was a "protected source".

Hartley, 40, from Brockley, and Bukarewicz, 45, denied conspiracy to commit misconduct in a public office and were found not guilty by a jury following a trial at the Old Bailey.

The jury was told that Hall accepted that he supplied stories to Hartley for which he was paid but he was not in the dock. He is due to be sentenced for misconduct in February.

After she was found not guilty, Hartley burst into tears and mouthed "thank you" to the jury before leaving the dock.

The trial heard that in March 2010 Hall gave the Whitehall editor information that went into an exclusive double-page spread about Mr Darling's budget before he stood up to deliver it to MPs. A financial trail revealed that Hall was paid £750 for the story.

He was also paid £500 for a story in December 2009 about celebrities including Kelly Brook being paid as part of a £1.3 million taxpayer-funded TV campaign publicising the Government website Directgov.

Prosecutor Zoe Johnson QC told jurors: "This is not a trial involving whistleblowing in a noble cause. It is a case in which Hall, the HMRC press officer, was motivated by greed and Miss Hartley, the journalist, was motivated by acquiring the next big scoop or exclusive.

"Many of you will have sympathy for journalists who expose mismanagement and inefficiency in government departments but that is not what this case is about."

Alexandra Healy QC, defending, said it would be "quite wrong" to convict Hartley of a plot to commit a criminal act, arguing: "She was doing her job. She did it well. She did what was asked of her and everybody knew what she was doing."

The journalist and mother of two, who was arrested by Operation Elveden officers in 2012, insisted the stories were in the public interest and at the time it never occurred to her that she was doing anything illegal.

Hartley justified the Budget leak by saying it was important for Sun readers to get the story before it was subjected to "spin".

Media commentator Roy Greenslade, who gave evidence in her defence, insisted that leaks were the "lifeblood" of political journalism in Britain and the cultivation of sources was a key part of the job.

Hall, who joined HMRC in 2009, received more than £4,000 directly from News International between April 2008 and May 2010.

After that, Bukarewicz channelled more than £13,000 between June 2010 and July 2011 and kept about £845 for her role, the prosecution said.

But in her defence, Bukarewicz, of Kentish Town, north west London, said Hartley had suggested the arrangement to Hall because he was a "protected source" and it was "standard practice at the Sun".

She denied taking a cut, saying she kept money back to pay shared bills and to buy plane tickets to Poland to visit her mother and attend her god-daughter's wedding.

Questioned on whether she ever asked her boyfriend about what he was doing, she said: "I trusted him so I didn't question much, as stupid as it sounds, but I didn't."

Ms Johnson said: "I'm going to suggest to you, Miss Bukarewicz, that you knew that what he was doing was illegal."

She replied: "No, I did not. I was not aware."