Public health officials are investigating a spa offering 'snail facials' in Chiang Mai, Thailand, as its mollusc mucus beauty treatments grow in popularity.

Inspectors turned up at the Reelle Clinic Institute Malin Residence, near Chiang Mai University, to check safety procedures after a string of high-profile actors and actresses started using the facility’s services.

The treatment involves placing snails on the face of customers. The molluscs leave a trail of mucus full of vitamins that are supposedly beneficial to human skin. Clinic owner Arnaud Decroix cited French research on the effectiveness of the technique, according to the Bangkok Post.

The inspection was carried out because the clinic is the first to offer snail facials in Thailand.

Decroix imported 100 Helix Aspersa Maxima snails from France – each of which went through the government’s foreign species inspection process to protect the local ecosystem. The clinic’s owner then bred the creatures. He now has more than 30,000 as his snail farm in Chiang Mai’s Hang Dong district. All snails in use get a two week rest after working at the clinic to ensure their welfare, according to Decroix.

Officials raised concerns about the repeated use of the snails on people with different skin types. The treatment must be hygienic so experts are testing the snails for possible bacterial contamination.

Chiang Mai’s deputy public health chief Surasing Wisarurat said the concept of a snail spa is not illegal – the treatment falls into the same category as fish spas, a pedicure where fish eat the dead skin off peoples’ feet. A recent US court case ruled that it was not illegal to stop a spa owner from using these fish in pedicure treatments for consumer protection reasons.

Environmentally, however, the Thai government classifies snails from other countries as ‘alien creatures’. This means the spa’s procedures will be scrutinised further.