The Nepali government says a British national has been detained for questioning about his involvement in anti-government protests by ethnic minority groups.

Home Ministry official Yadav Koirala said Tuesday that if the man was found to have been involved in the protest then his visa would likely be revoked and he would be deported.

The British man identified as Martin Travers, 41, was photographed at a rally near the prime minister's office wearing a red headband used by the protesters.

Koirala said Travers claimed he was forced to take part in the protest and if that was true he would be freed later Tuesday.

Ethnic protesters have been demonstrating since Sunday in the capital Kathmandu against a new constitution adopted last year.