Myanmar's ruling military jailed on Friday a former British ambassador and her husband for a year each for breaching immigration rules, a junta spokesman said.

Vicky Bowman, who served as envoy from 2002 to 2006, was detained last month for failing to declare she was living at an address different from the one listed on her foreigner's registration certificate.

Htein Lin, a Myanmar national and prominent artist, was arrested for helping his wife reside at an address different to their registered home in commercial hub Yangon.

The couple, who have a daughter, could have been jailed for up to five years.

Since carrying out a coup last year, Myanmar's military has carried out a bloody clampdown on dissent and battled forces opposed to the takeover. Scores of foreign nationals have been caught up in the crackdown.

Local media said the hearing took place at a court inside Yangon's Insein prison.

A spokesperson for the United Kingdom's foreign ministry said it would "continue to support Ms Bowman and her family until their case is resolved".

Ties between Myanmar and its former colonial ruler Britain have soured since the military's takeover, with the junta this year criticising the UK's recent downgrading of its mission in the country as "unacceptable".

Before serving as ambassador, Bowman was the second secretary in the British embassy from 1990 to 1993.

She is now director at the Myanmar Centre for Responsible Business and is a fluent Burmese speaker.

Htein Lin took part in a 1988 student uprising against a former junta, and later spent years underground.

He was arrested in 1998 and imprisoned for allegedly opposing junta rule.

After he was freed in 2004, he came to the attention of then-ambassador Bowman for a series of paintings he completed in jail using smuggled materials.

She persuaded him to let her take the politically sensitive artwork, which depicted his life behind bars, for his own security.

He later proposed to her during a holiday in Britain, and the pair married in 2006.

"The latest reports on the conviction of the former UK ambassador and her Burmese artist husband are extremely concerning," Amnesty International's deputy regional director for campaigns Ming Yu Hah said.

The United Nations Human Rights Office in Geneva said it was "deeply shocked that the de facto authorities have sought to punish people who have been committed to the development of the country".

The British government has sanctioned several military-linked companies and individuals following the army's power grab.

Bowman and her husband were arrested the day before London announced new sanctions on companies it said had helped raise funds for the military during its 2017 crackdown on the mostly Muslim Rohingya minority.

Australian economist Sean Turnell -- who worked as an adviser to civilian leader Aung San Suu Kyi -- was detained shortly after the coup and is accused of breaching the colonial-era official secrets act.

Japanese filmmaker Toru Kubota is currently being held in Insein prison, after he was arrested last July near an anti-government rally in Yangon.

He was the fifth foreign journalist to be detained in Myanmar, after US citizens Nathan Maung and Danny Fenster, Robert Bociaga of Poland and Yuki Kitazumi of Japan -- all of whom were later freed and deported.

More than 2,200 people have been killed and 15,000 arrested in the military's crackdown on dissent since it seized power, according to a local monitoring group.