The allegations against Peter Slipper, the Australian parliamentary Speaker, by a male employee were highly salacious, involving lascivious text messages, showers taken with the door open and a neck massage, which elicited moans of pleasure. They were also highly politically charged, since Mr Slipper had defected from the opposition and was helping to prop up Julia Gillard's minority government.

The Speaker denied the allegations, but stood aside while James Ashby's claims of sexual harassment were investigated. Two months on, a murky tale of political derring-do is emerging, with Mr Ashby accused of conspiring with senior opposition MPs and a journalist to undermine the Labor government and blacken Mr Slipper's reputation.

"Slippery Pete", as he is known in political circles, had long been unpopular in his own Liberal Party, and was also notorious for his lavish parliamentary expenses. But when he accepted Ms Gillard's offer to resign from the Liberals last November in exchange for the Speaker's job – thus increasing the government's majority to three – the dislike of his former conservative colleagues turned to loathing.

There was, therefore, much glee on the opposition benches when The Daily Telegraph, a Sydney tabloid owned by Rupert Murdoch, broke the harassment story on its front page. It depicted Mr Ashby, 33, as the affronted victim of unwanted sexual advances.

Mr Ashby stayed in Mr Slipper's flat when he first moved to Canberra, and the story – by Steve Lewis, a parliamentary journalist – also claimed that the 62-year-old left the bathroom door open while showering. He also allegedly asked for a massage by his young employee.

This week a different picture of Mr Ashby emerged from documents filed with the Federal Court by the Speaker and the government, both of whom he is suing. They include sexually explicit text messages – not from Mr Slipper to Mr Ashby, but vice versa – and claims that the latter held secret meetings with senior Liberal figures weeks before he made his harassment complaint.

Most of the texts are unprintable, but in one of them Mr Ashby told his boss: "I'm going to smack *! Arhhhhhhh."

The documents also reveal that, two weeks before the allegations exploded into the media, Mr Lewis texted Mr Ashby, saying: "We will get him!!" Mr Ashby also allegedly sent extracts from Mr Slipper's private diary to Mr Lewis, and also to Mal Brough, a former federal minister seeking to be the Liberal candidate for the Speaker's Queensland seat at the next election.

Mr Brough has admitted meeting Mr Ashby three times before the complaint was lodged, and discussing the matter with him. Put all that together with revelations that Mr Ashby and a colleague in Mr Slipper's office, Karen Doane, approached Mr Brough for jobs – and that he tried to help Ms Doane – and the whole affair starts to look decidedly fishy. That is certainly what Mr Slipper and the government think. Their lawyers have accused Mr Ashby of orchestrating a "calculated, duplicitous and deceitful scheme" to besmirch the Speaker and assist the Liberals and Mr Brough.

Since the documents came to light, Anthony Albanese, leader of the House of Representatives, has done his best to implicate the opposition leader, Tony Abbott, claiming that the latter's MPs are "up to their necks" in a conspiracy. He has also charged Mr Lewis with trying to "sabotage" the government. The court papers reveal that Mr Ashby was flown to Sydney and put up in a hotel at the Telegraph's expense while Mr Lewis was preparing his story. He had told his employer he was taking sick leave.

A colourful figure, Mr Slipper relished the Speaker's role, reviving a long-abandoned tradition of entering parliament after proceeding formally through the building, dressed in a robe and white bow tie, escorted by a parliamentary attendant and the serjeant-at-arms bearing a golden mace.

Message trail: The Murdoch connection

"We will get him!"

Text allegedly sent by News Limited journalist Steve Lewis to Peter Slipper's aide, James Ashby, regarding Mr Slipper. Further messages include: "I will sort out payment". News Limited is the Australian arm of Rupert Murdoch's media empire.

"… Pass the text message in hard copy only to Mark – let him move it forward. Backup phone, delete messages, put in safe and let it be. A smoking gun usually means someone has already been shot! Don't let it be you – please."

A document submitted to the Federal Court details this message sent from a person named as 'Tania' to Mr Ashby on 2 February, highlighting his association with Caloundra MP Mark McArdle, of the Liberal National Party, before allegations against Mr Slipper emerged.

"Mal did email me confirming he forwarded my CV… Great result"

Text allegedly sent by Karen Doane, a Slipper aide, to Mr Ashby, as the pair allegedly angled for new jobs with Liberal National Party through Mr Slipper's political rival Mal Brough. Ms Doane reportedly said she was considering bringing her own sexual harassment case against Mr Slipper.

"I have no respect for Mal Brough and never will."