Vicky Bowman and her Burmese husband run a centre which encourages businesses to respect human rights.
The UK’s former ambassador to Myanmar, Vicky Bowman, has been arrested in the main city, Yangon.
Sources have told the BBC Ms Bowman and her husband were arrested at their home in the city on Wednesday and are being held on an immigration charge.
The UK embassy say they are providing consular assistance to Ms Bowman, who runs the Myanmar Centre for Responsible Business (MCRB), based in the city.
She served as UK ambassador to the south-east Asian state from 2002-2006.
Ms Bowman is married to Htein Lin, a Burmese artist and former political prisoner.
The MCRB describes itself as “an initiative to encourage responsible business activities throughout Myanmar”. It co-operates with the Institute for Human Rights and Business (IHRB) – whose aim is “to make respect for human rights part of everyday business”.
Myanmar’s military regime has been accused of widespread violations of human rights.
Early this month, generals extended their emergency rule until 2023 as the country remains riven by internal fighting.
The junta seized power last year after overthrowing Aung Sung Suu Kyi’s democratically-elected government.