Nepal’s government has summoned the UK ambassador in protest at the arrest by British police of a Nepali army officer on allegations of torture.
Col Kumar Lama, a serving member of Nepal's army who was visiting the UK, is accused of torturing a detainee in 2005 during Nepal's civil war.
British law allows prosecutors to act against people suspected of torture no matter where it took place in the world.
The arrest is based on a complaint filed by Advocacy Forum Nepal on behalf of a man who says he was tortured by Colonel Lama in army custody.
Nepal says Britain is breaching its sovereignty by carrying out the arrest.
Colonel Lama has been serving with the UN mission in Sudan.
See reports by the BBC and AFP.