James Mawdsley, 25, could be held in the "dog cells" of Insein prison, Burma, after being arrested while distributing anti-government leaflets. It is the second time Mr Mawdsley has been arrested in Burma.
Yesterday Mr Mawdsley's father, David, said he was horrified by what had happened. "We heard last week that he had been arrested and at the time there was talk that they believed he was a mercenary," he said, from London.
"In the end they charged him with illegal entry to the country and he pleaded guilty, but no one expected him to get five years. I am really worried about how he will manage both physically and mentally. He is very passionate about human rights and he is a very brave young man, but sometimes I think he is too brave."
It is understood that Mr Mawdsley was arrested a week ago in the town of Moulmein in the Shan province of Burma, close to the border with Thailand. At his trial the judge said that Mr Mawdsley had been found distributing leaflets criticising the Burmese regime which seized power in 1988, destroying the nascent democracy movement headed by Aung San Suu Kyi. Since then thousands have been killed or have disappeared under a regime widely condemned for its abuse of human rights.
If Mr Mawdsley is treated as a political prisoner he may be held in the prison's dog cells, the converted kennels formerly used by the prison guards to keep their dogs.
"The conditions are very poor and there is no reason that Mr Mawdsley will get any different treatment because he is British," said Yvette Mahon, spokeswoman for the Burma Action Group. Last year the Norwegian Consul, Leo Nichols, died after being held in Insein prison, where he was refused medical treatment.
A spokesman for the campaign group Amnesty International said: "We have had reports of bad conditions in respect of the food and the fact that political prisoners may be subjected to torture."
Mr Mawdsley, originally from Ormskirk, Lancashire, was allowed access to a lawyer. His legal team, supported by the British and Australian authorities, is considering an appeal against the five-year sentence, the maximum for offences which breach the 1947 Burmese Immigration Act.
He was arrested for the first time and deported by the regime in September last year after chaining himself to railings outside a school in the capital, Rangoon, and spraying a wall with the slogan "metta", which means love and kindness. After his release Mr Mawdsley, who has joint British and Australian citizenship, said: "I have no regrets. I am proud to have brought attention to the human rights situation in Burma."
A spokesman for the Foreign Office said last night that it had demanded early access to Mr Mawdsley in prison and was in contact with his defence team. His mother is understood to be travelling from Australia to Burma to visit him.
It is 10 years since the military junta, now known as SPADC or the State Peace and Development Council, crushed the democracy movement. In elections held in 1990 Suu Kyi's party obtained 82 per cent of the vote but the junta refused to accept the result.Reuse content