It was a prank on a boozy bender for rugby stars.

But it has now seen Super League star Keith Mason go to court – suing the Huddersfield Giants for more than £300,000 for unfair dismissal.

Mason, 31, who played for the Giants for seven years, was sacked in October last year over a dodgy picture on his Twitter account.

Yesterday, His Honour, Judge Andrew Saffman at Leeds Crown Court, heard that Mr Mason’s then girlfriend Lauren Harwood, had found a picture of a man’s backside on his iPhone after he returned from a three-day drinking binge, known in the rugby league world as Mad Monday.

The picture had been taken of fellow player Scott Moore’s behind during the annual end of season blow-out.

The offensive image was put on Twitter on Tuesday, September 18 and remained there for almost 48 hours until Mr Mason deleted it.

But despite the club accepting that Ms Harwood had posted it to Twitter without Mr Mason’s knowledge he was still dismissed for gross misconduct two weeks later.

The club said he had brought it into disrepute by not deleting it soon enough.

Mr Mason said he did not take the offending picture down as he was “hung over” and recovering from Mad Monday.

Four complaints were received but all were after the picture had been deleted.

Mr Mason appealed his sacking but club vice-chairman Dr Paul Morgan dismissed it.

Mason still had three years to run on his contract at the time.

Backed by his good friend, world famous boxer Joe Calzaghe, Mr Mason took to the stand to give more than three hours of evidence.

Mr Mason says he believes the timing of his dismissal was suspicious as two new players who played his position, prop-forward, had been signed over the summer.

Martin Budworth, counsel for Mr Mason, said there were aspects of the dismissal that “did not stack up as a genuine dismissal”.

And he said Mr Mason called into question the club’s sincerity in its belief that he had committed gross misconduct.

He said one of the alleged complaints about the tweet had come from someone known to be a “drinking partner” of Giants managing director Richard Thewlis.

Richard Thewlis
Richard Thewlis

And he said there appeared to be tampering with another one of the email complaints by the club as it did not reveal when it was received.

Mr Budworth said that Mr Thewlis was desperate to get rid of him to free up space in the salary cap for the incoming Craig Kopczak and Stuart Fielden.

Mr Budworth asked Mr Thewlis if Mr Mason’s £95,000 salary was a “good contract”.

“How many were earning more than him?” he asked.

Mr Thewlis replied: “There were some, maybe Eorl Crabtree, Danny Brough, Jason Chan, Luke O'Donnell and possibly David Faiumu.”

Mr Budworth said new players Kopczak and Fielden were on £60,000 and £55,000 respectively.

He said: “It was a case of getting two for the price of one wasn’t it?”

Mr Thewlis said: “That’s how the maths work out but it was nothing to do with it.”

Mr Budworth said the club had six other players able to play in the prop position and Mr Thewlis had sent a final plea to Mr Mason’s agent titled “FINAL ATTEMPT” in a bid to offload him to Wakefield Trinity, after a deal with Widnes failed to materialise.

But that too did not come off as Mr Mason planned to stay at the Giants until the end of 2015 in a bid to get his testimonial.

Mr Mason told the court Mr Calzaghe had offered to host some testimonial events, as had his other celebrity friend, Hollywood star Mickey Rourke.

He calculated the loss in earnings from missing these would be in the region of £60,000 but said Hull player Richard Horne had made over £100,000 during his testimonial year.

And he said he had a deal with fellow Giants’ player Kevin Brown, who signed the same year as him, that he would get the testimonial first.

Paul Wilson, counsel for Huddersfield Giants Limited, accused Mr Mason of not respecting the club or the RFL’s family values policy.

He said: “You’ve been disciplined before in 2009 for missing training to go to a party with Micky Rourke in London.

“I suggest this is similar, you just do what you want don’t you?”

“Not really,” said Mr Mason.

Mr Wilson alleged Mr Mason frequently used “unattractive language and behaviour on Twitter” and said he had tweeted support for supplements brand Muscleforce, a rival of one of the Giants’ main sponsors Muscle King.

Mr Mason said he was a good role model and had not received any money for the Muscleforce tweet.

The case continues.