The Ministry of Agriculture and Cooperatives on Friday ordered the Milk Board to suspend Thaimilk Dairy Cooperative as a supplier for the National School Milk Programme after a private school in Bangkok complained about milk it had provided.
The move came after Patai Udom Suksa School on Tuesday sent a circular to inform parents that the school had ceased giving students government-subsidised milk supplied by the cooperative after finding it was off.
The letter later went viral on social media, sparking concern among parents elsewhere fearing their children might fall sick from drinking milk from the same supplier.
School director Primprai Supapodok said the milk was supplied by Thaimilk Dairy Cooperative, a firm based in Saraburi's Muak Lek district.
"At first, we only found a problem with two cartons of milk given to Grade 2 students. The milk was thicker than usual and looked a bit like jelly despite the milk not having reached its expiry date.
"The next day, we had the same problem with 18 more cartons, so we decided to stop giving the milk to our students,'' Ms Primprai said.
After that, samples of the milk were collected and sent to be tested at the Ministry of Public Health.
"This is not the first time this has happened. The school had a similar problem in 2016," she said.
Agriculture and Cooperatives Minister Grisada Boonrach said the Milk Board, the veterinarian and the Dairy Farming Promotion Organisation of Thailand (DPO) have launched an investigation to find the cause of the problem. This will include checking how the milk was stored, and transported.
"I've ordered the Milk Board to temporarily remove Thaimilk Dairy Cooperative from the list of suppliers for the free school milk scheme. We do not know yet if the problem occurred during the production process or after," he said.
If the results come back saying the production process is to blame then Thaimilk Dairy Cooperative will be permanently removed from the list of suppliers for the school milk scheme, he added.
Mr Grisada said he also ordered the Milk Board to inspect milk from all the scheme's suppliers to ensure quality meets Ministry of Public Health standards.
The school milk scheme has been managed by the Milk Board, which is comprised of the DPO, the Livestock Department and the Cooperative Promotion Department, since 2009.
The Milk Board selects suppliers for the scheme and oversees standards in processing plants and the quality of their milk.