Authorities in Europe are working to establish whether the man suspected of carrying out the most deadly terrorist attack in New Zealand’s modern history had any links to far-right groups on the continent.

Since Friday, officials in Turkey, Bulgaria and Greece have begun formal investigations into the alleged gunman’s extensive travel through Europe in the years before he moved to New Zealand.

Brenton Harrison Tarrant, a 28-year-old Australian, appears to have travelled extensively throughout Europe, the Middle East and Asia, including to Turkey, France, Pakistan, Bulgaria, Hungary and North Korea.

The “manifesto” published online in the minutes before Tarrant’s alleged attack on two mosques in Christchurch on Friday, which left 50 people dead, claimed that it was while travelling through western Europe in 2017 that his views on immigration “dramatically changed”.

Tarrant wrote that while traveling through France, Portugal and Spain he was horrified by the killing of Ebba Åkerlund, an 11-year-old girl, when an Uzbek man, Rakhmat Akilov, rammed his truck into a group of pedestrians in Stockholm in April 2017.

Two of the rifles used in the Christchurch shooting had references to Åkerlund scrawled on them, among other messages.

Brenton Tarrant appears in court on a murder charge in Christchurch on Saturday. Photograph: Mark Mitchell/AAP

The manifesto also referenced the 2017 French elections, saying he felt “despair” at the defeat of the far-right Front National leader, Marine Le Pen.

The manifesto gives the impression of being particularly aggrieved about immigration in France. He wrote that he felt “fuming rage and suffocating despair” at “invaders”, claiming French people were “often in a minority themselves”.

While Tarrant was not on the radar of intelligence agencies in Australia or New Zealand, experts believe it is likely he had been influenced by the far-right “identitarian” movement.

Formed in France in 2016, the movement features common tropes about what adherents claim is the replacement of European culture with a non-European one, many of which were echoed in the document, titled “The great replacement”.

The counter-terrorism expert Greg Barton, from Deakin University in Melbourne, said it appeared Tarrant shared a number of ideas with the movement.

“It’s just speculation of course, but it would make sense in that context that he has picked up on those ideas while travelling in Europe at that time,” he told Guardian Australia.

The manifesto also expressed environmental concerns, something Barton said was a tenet of the “dominion movement”, a group he described as “a New Zealand manifestation of European identitarianism”.

The dominion movement took down its website after Friday’s shooting, and put out a statement saying it “categorically and without reservation condemns the events in Christchurch”.

“[Neither] our movement nor any of its members have ever had any communication or association with the perpetrator,” the group said in a note on the closed page.

Its website previously stated that “Europeans are the defining people of this nation”.

The document claims its author made money on the cryptocurrency Bitconnect, which was widely described as a Ponzi scheme before it was shut down in 2018. Reports have also stated that in other social media posts Tarrant indicated he used inheritance money after his father’s death to fund some of his travel.

Greek officials said on Sunday that Tarrant had visited Greece briefly in 2016.

A statement from the ministry of citizen protection said he flew in from the Turkish city of Istanbul on 20 March and stayed a few days on the islands of Crete and Santorini.

Tarrant also had two stopovers at a Greek airport in November and December that year. A Greek police source told Agence France-Presse that investigations into Tarrant’s movements were continuing.

He also made two trips to Turkey in 2016 for a total of 43 days, according to the Turkish state broadcaster TRT World. He visiting the country from 17-20 March and arrived back on 13 September before leaving on 25 October.

The broadcaster quoted a Turkish official saying authorities were “currently investigating the terrorist’s movements and contacts within the country”.

The manifesto contained many explicit references to the Ottoman empire, Turkey and its president, Recep Tayyip Erdoğan, stating Muslims should be driven out of the part of Turkey that lies west of the continental divide between Europe and Asia.

On Sunday, Erdoğan used an edited version of Tarrant’s video of the shooting to galvanize support before local elections at the end of the month.

According to Bulgaria’s chief prosecutor, Sotir Tsatsarov, Tarrant visited Bulgaria from 9-15 November last year, claiming he wanted “to visit historical sites and study the history of the Balkan country”.

Local media quoted Tsatarov as saying the country would investigate whether this was “correct or if he had other objectives”.

Investigators said Tarrant arrived in Sofia from Dubai on 9 November and hired a car the following day to visit historical sites in 10 locations. He left on 15 November on a flight bound for neighbouring Romania’s capital, Bucharest, where he hired a car to travel to Hungary, Tsatsarov said.

The Australian also travelled by bus across Serbia, Croatia, Montenegro, and Bosnia-Herzegovina from 28-30 December 2016.

In the livestream of the attack on Friday, a Serbian nationalist song could be heard playing through his car speakers.

According to radio reports, Tarrant also visited Spain last year. The Cadena Ser network said he spent one night in a hotel in the southern city of Jerez in February 2018. Hotel staff told the local station that Tarrant’s behaviour had been that “of a normal man – a little reserved”.

Spanish police said they had no information on Tarrant or his stay.

Additional reporting by Sam Jones in Madrid