Sri Lanka has deported a British tourist for having a tattoo of Buddha on her arm, which a court said was an insult to the island's main religion.

Naomi Coleman, 37, a nurse left on a London-bound flight on Thursday after being detained since her arrival on Monday from neighbouring India.

"I just want to get out of this place. I have come twice to Sri Lanka, but I have never faced this with my tattoo," Coleman told Reuters news agency shortly before she was deported.

If there is a rule like this, Sri Lankan authorities should clearly say that Buddha tattoos are banned. I am a practicing Buddhist and Buddhism is all about compassion and kindness

Naomi Coleman, British national

Legally, there is no ban on a Buddha tattoo in Sri Lanka, but the predominantly Buddhist nation is very sensitive about its religion.

"If there is a rule like this, Sri Lankan authorities should clearly say that Buddha tattoos are banned. I am a practicing Buddhist and Buddhism is all about compassion and kindness," she said.

Buddhism is accorded the "foremost place" in Sri Lanka's constitution and about 70 percent of the island's 20 million people are Buddhist.

Authorities spotted Coleman's tattoo upon her arrival in Sri Lanka.

Senior immigration official Chulananda Perera said the court had decided to deport Coleman partly because she could have been "vulnerable" if allowed to stay.

"Some Sri Lankans could get offended," Perera said.

It was not the first time a tourist with such a tattoo has run into trouble in Sri Lanka.

In 2013, authorities denied entry to a British man for his tattoo of Buddha.