A naughty zoo orangutan grabbed a woman's boobs while she was posing for pictures.

Footage shows the primate grinning, hugging, and embracing the tourist for photo-ops in Bangkok, Thailand on June 28.

But mid-session, the ape named Nhong cheekily cupped the petite holidaymaker's breasts before she burst out laughing.

Tourist Sirilak Palathumma said: ‘The monkey was so cute and very smart. He made everyone laugh with his tricks.'

The orangutan lives in an enclosure at the Safari World zoo in the Thai capital. One of his roles is to stand with tourists as they have pictures taken.

However, he has learned the amusing trick of touching women's cleavage and kissing them - with encouragement from the handlers and other visitors.

Willing women are even flocking to the zoo to be groped by the ape because of the popularity of the videos on social media.

Despite the popularity among locals, animal rights groups have raised concerns about orangutans being used for the entertainment of tourists in zoos in Thailand.

Suddan Wisudthiluck, from the Thammasat University, Anthropology Department, said that animals are 'seen as friends or family members'.

But animal rights groups including PETA have previously called on the photo sessions with orangutans to be banned as they 'humiliate and exploit' the creatures.