About 10% of Buddhist monks and novices nationwide are addicted to drugs, according to an expert at the Religious Affairs Department.
Manop Polparin said the use of drugs has spread to temples, with about 10% of an estimated 300,000 monks reported to have sought treatment at rehabilitation centres.
Efforts to solve drug problems in the temples have failed due to poor co-operation from senior monks and lack of funds, he said.
Many temples refused to co-operate with police.
"Senior monks would not admit junior monks and novices at their temples were addicted to drugs for fear the public would lose faith in the religion ... As a result, nobody believes the use of drugs has been rampant among monks," said the expert.
Budget constraints have also hampered efforts to tackle drug problems in the temples. The Religious Affairs Department has been given only three million baht this year to help rehabilitate addicted monks.
"With only three million, each addict receives only 10 baht for rehabilitation. The amount is not enough to help addicts kick the habit," Mr Manop said.
He urged senior monks to screen people who want to enter monkhood more thoroughly.
Meanwhile, Deputy Education Minister Chamlong Krutkhunthod has asked the Religious Affairs Department to publish books on Buddhist teachings for distribution to business premises, hotels and tourist spots. The minister believes such books would help readers, especially young people, become better persons.