A British man who leaked financial information about one of Russia’s most powerful politicians is pleading with the Australian government to allow his family to live in the country, despite their claim for asylum having been refused.

In 2014 Nicholas Stride provided secret documents to media about the financial dealings of Russia’s former deputy prime minister, Igor Shuvalov, when he was a contractor for him.

Stride says he fled to the UK in 2010 with his Russian-national wife and their two children after they were allegedly threatened and told not to leave Russia. Fearing the UK was not far enough out of reach, the family moved to Australia and say they have spent years living off the grid in the remote Kimberley region in the far north of Western Australia.

For several years the family lived essentially in hiding, fearing separation, with neither child able to attend school.

“We travelled non-stop until we reached Broome and soon we found a safe place to live in where a kind family took care of us,” Stride’s daughter, Anya, wrote in a letter in 2017, provided to the Guardian by Stride.

“We were so secluded from the rest of the world for two years that I’d forgotten how to socialise.”

Anya Stride, now 18, told the ABC the family ended up “homeless on a beach” and became increasingly desperate when they ran out of money.

“Mum made bread and we had packs of rice and baked beans … we lived like that for three months … off fish and rice,” she said.

Stride recently authorised the journalist Michael Weiss to identify him as the source behind a series of reports in Foreign Policy about Shuvalov’s use of offshore accounts and tax havens.

Weiss reported that Shuvalov, one of Russia’s richest officials had accumulated a $220m fortune and that he allegedly made extensive use of offshore schemes and a now-defunct bank in Kyrgyzstan.

In a 2014 interview Shuvalov denied any wrongdoing. He said he fully complied with Russian law, with his foreign assets held in the equivalent of a ‘blind trust’. In the 1990s he worked in private business, he added.

Weiss went public about Stride’s identity in a bid to find help for his former source.

A former source of mine, who passed along secret documents about Russia’s Deputy Prime Minister Igor Shuvalov’s unexplained wealth and expenditures, is facing, along with his family, deportation from Australia. Here’s the story he was a source for: https://t.co/NJWA6HRBl7 — Michael Weiss (@michaeldweiss) January 16, 2019

Stride and his family have applied for asylum in Australia but have been rejected. The Refugee Review Tribunal’s decision, sections of which have been seen by Guardian Australia, acknowledged the family had real fears, but said they could not be given protection.

“The delegate found that although the applicants’ claims referred to an extremely powerful political figure in the Russian Federation, the nature of the claims against him are not political in nature,” the decision said.

“It is apparent that the danger they fear, which the delegate accepted as being real, is for reasons other than those intended by the grounds laid out in the Refugees Convention.”

There have been a number of cases of alleged Russian targeting of dissidents and other individuals in the UK. In March 2018 a former Russian spy, Sergei Skripal, and his daughter, Yulia, were poisoned with a Novichok nerve agent.

The prime minister, Theresa May, has said it was almost certainly authorised by the Russian state.

In 2006 the Russian critic Alexander Litvinenko was murdered with polonium, a radioactive isotope, put into tea.

Stride told Guardian Australia he was under no illusion about his safety if he returned to the UK, and that the family felt Australia was far enough “out of reach” of Russian retribution.

In assessing Stride’s case the Australian tribunal concluded the UK met international standards of protection in taking reasonable measures to protect citizens, and said it was not satisfied Stride’s wife, Ludmila Kovaleva, faced a real chance of persecution – as defined by the UN refugee convention – if she was sent back to Russia.

“I agree with their findings that we were not part of an opposing political party, we are part of a democratic commonwealth nation and it’s a duty of everyone to expose corruption and crime if witnessed,” he said.

“I am no martyr, just an everyday person with all the imperfections and problems of life like most people, sometimes you see things that are so bad you have to act. I did and I’m getting punished for it.”

In a letter to the then minister for immigration, Peter Dutton, Stride’s wife asked for her and her family to be allowed to stay in Australia, alleging death threats from people in Russia.

Stride said the family had exhausted all legal options and had appealed to successive immigration ministers for intervention to stop him and his three children being deported to the UK and his wife to Russia.

Stride and his wife have separated, and he and his son have since fled to south-east Asia, claiming they feared the son would be deported by Australia to the UK. They both have short-term Australian travel bans for overstaying their bridging visas, which expired in September. Anya Stride is still in Australia.

Stride said he was now trying to get residency in any country so the family could be reunited.

“It’s a shit plan I know, and I have huge regrets, we are just living on the edge and have been for many years,” he said.

“I’m a good person, with great kids. I’ll do anything to give them back a life. They have lost so much because of me.”

Australia’s Department of Home Affairs said it did not comment on individual cases or matters which were before the court.

Stride said he had asked the immigration department to resolve their situation many times over the years but nothing was done.

Now he was again requesting residency from Australia, or otherwise another country such as New Zealand or Canada.

“We want to be somewhere living safe, living normally,” he said.

“Australia is everything they know.”

Multiple calls to Shuvalov’s spokesperson went unanswered on Friday.