Authorities in Myanmar have detained Britain’s former ambassador to the Southeast Asian nation, where a military junta seized power last year, three people with knowledge of the situation said Thursday.

Vicky Bowman, who currently runs the Myanmar Center for Responsible Business (MCRB), and her husband, Htein Lin, a Burmese artist and former political prisoner, were detained on Wednesday, the sources said, asking not to be named due to the sensitivity of the issue.

A source with knowledge of the situation said Bowman and her husband had been charged with immigration offenses.

The arrest comes as Britain announces it is imposing fresh sanctions to target military-linked businesses in Myanmar and joining the case against Myanmar in the International Court of Justice.

Britain is the fourth country after the Maldives, Netherlands and Canada, to vow formal support for the case brought by the Gambia against Myanmar to determine whether its military conducted genocidal operations against Rohingya Muslims in 2016 and 2017.

Three companies are being penalized with sanctions “in an effort to limit the military’s access to arms and revenue,” the British government said in a statement on Wednesday.

A spokesperson for the Myanmar junta did not answer repeated calls seeking comment.

Myanmar has been in political and economic chaos since the military overthrew an elected government in early 2021.

More than 15,000 people have been arrested and 12,119 remain in detention, according to the Assistance Association for Political Prisoners, an activist group. The junta claims that figure is exaggerated.

A British embassy spokesperson in Yangon said: “We are concerned by the arrest of a British woman in Myanmar. We are in contact with the local authorities and are providing consular assistance.” The spokesperson did not name the individual.

Bowman, 56, served as ambassador to Myanmar from 2002 to 2006 and has more than three decades’ experience in the country.

Her husband Htein Lin, 55, is one of Myanmar’s most famous artists and a veteran activist who spent 6 1/2 years, between 1998 and 2004, in prison for his opposition to an earlier junta.

The couple had been remanded in custody and were being sent to Insein prison, a source said, the notorious jail on the outskirts of the commercial capital of Yangon where many political prisoners are held.

The source added their young daughter remained “safe and well.”

Bowman is the latest foreigner to be detained in Myanmar.

Sean Turnell, an Australian economist and longtime adviser to deposed leader Aung San Suu Kyi, and Japanese freelance filmmaker Toru Kubota also remain in detention.

Their governments have called for them to be released.