"The ministry's inspector generals will form a probe team to find out what happened," Wijit said.

The Education Ministry has barred state schools from accepting donations during the student admission period in a bid to prevent schools from trading seats for "tea money".

The Samsen Wittayalai School, however, has already announced which students have been accepted into its English programme and requested a Bt100,000 donation from parents of the successful applicants. The donation is not mandatory.

"No matter what, Samsen Wittayalai School should get a rebuke for asking for donations at this time, because other parents could perceive this as a tea-money practice," Wijit said.

One parent, who spoke on condition of anonymity, said she never received any information about the Bt100,000 donation.

"When I asked the school about the donation, I was told that I could pay it in instalments," the parent said.

Samsen Wittayalai School director Wisarut Sonthichai said that the English programme at his school needed donations because the Bt35,000 tuition fees could not cover actual costs.

"Students learn in air-conditioned rooms. Teachers are native speakers with master degrees and teaching materials are imported from overseas," he said.

He insisted that even if parents could not provide donations, their children would still enjoy the right to be part of the English programme. "It's not a mandatory condition," he said.