The Austrian identitarian leader, Martin Sellner, has been subjected to further searches by Austrian police in connection with the Christchurch shooter, according to Austrian media reports and videos on Sellner’s own YouTube channel.

The investigation has also reportedly widened to include Sellner’s US-based fiancee, Brittany Pettibone, and her own alleged connections with Australian far-right figure Blair Cottrell.

Austrian newspaper Die Presse reported on 18 June that two apartments in Vienna were searched by the prosecutor’s office in Graz, which has been investigating Sellner’s connections to the Australian, Brenton Tarrant, who is currently on trial for the murder of 51 people in Christchurch, New Zealand, in March.

In two German-language YouTube videos, Sellner offered his own account of the investigation. In the first, which he says was before an interview with police, Sellner says that police removed devices from his home, and that the reason was a “strong suspicion of forming a terrorist organisation with Brenton Tarrant”.

In the second video, Sellner shows what he claims is an excerpt from the warrant police used in raiding his apartment. Visible on the warrant in German are prosecutors’ reasons for carrying out the search, including “The Manifesto the Great Replacement”, which was released by Tarrant, “the results of a financial analysis”, and the suspicion that Sellner was cooperating with Tarrant in a terrorist and “structurally fascist” organisation.

Sellner was first connected with Tarrant after it emerged that the accused had made a €1,500 donation to Sellner’s Identitarian organisation. Die Presse reported that prosecutors were looking for “accounting records” and evidence of further donations from Tarrant to Sellner.

Another newspaper, Der Standard, reported that the investigation had widened to include Sellner’s “partner”.

Sellner’s fiancee, prominent far-right YouTuber and author Brittany Pettibone, announced on her own Twitter account on 18 June that she had been notified she was under investigation.

According to Pettibone, the reason was an interview she had done with Cottrell in January 2018. That interview is still available on “alt-tech” video platform, BitChute. In it she describes him as an “anti-Islam activist” and discusses his conviction under Victoria’s Racial and Religious Tolerance Act after he publicised a lurid Mosque protest in Bendigo featuring a mock beheading.

Pettibone claimed that a second reason was that she received an email from a person she did not name asking if Sellner “could give advice to Blair Cottrell regarding building up the rightwing movement in Australia”.

Sellner and Austrian prosecutors did not respond to requests for comment. When contacted, Brittany Pettibone declined to comment on the developments.

When asked if they were aware of investigations into a possible organisational connection between Tarrant and Sellner, New Zealand police said via email they were making “a large number enquiries, both across New Zealand and internationally” but they were “not in a position to go into specifics around those enquiries”.

In March, Austrian authorities commenced their investigation of Sellner’s connections with the Christchurch killer after it emerged that he had received a donation from Tarrant.

Last month, authorities revealed that contacts between the two men had been even more extensive, involving friendly email exchanges and an invitation by Sellner for Tarrant to join him in a beer or coffee if he ever came to Austria.

Sellner’s immigration status in the US, where he had planned to marry Pettibone this summer, was changed following that disclosure, preventing him from entering the country.

Pettibone was the focus of controversy last month after she presented Sellner’s case to a meeting of a local Republican party branch in Idaho, where she lives.

Sellner’s Identitäre Bewegung Österreichs (IBÖ) is part of a larger far-right Identitarian movement with branches in most western European countries, North America and New Zealand.

Sellner denies any connection with the events in Christchurch or the suspect. He released a video online saying, “I have nothing to do with the terrorist attack.”