Crime Suppression police are anxiously waiting until Prakitpao Thomthitchong, the famous physics tutor who's now hospitalised, is stable enough to tell them about how he got so much ephedrine in his body, as he is the one who knows best who gave the drug to him.

Deputy commander Colonel Anuchai Lekbumrung, who heads the ephedrine investigation team, said yesterday that the evidence so far had not helped police see how the psychotropic substance had got into Prakitpao and who had done it.

On Friday the Criminal Court banned any press conferences or contact with Prakitpao, so police will have to wait for the patient's condition to improve and seek the court's permission before interviewing him, Anuchai said.

Despite Pemmika Veeracha-traksit's detailed testimony at Friday's court hearing, investigators still want to question Pemmika, who claims to be a close friend of Prakitpao, on Thursday as scheduled because they believe she was with Prakitpao in the 48-hour period before he was admitted to Srithanya Hospital.

Anuchai has assigned officers to check sources of the substance, including some body-building websites that reportedly sell it, and ordered them to bring anyone distributing it illegally to justice.

Somchai Chakrabhand, director-general of the Mental Health Department, had a possible explanation for why Srithanya doctors had failed to record Prakitpao's information even though he had been admitted to the hospital on February 19.

Somchai said the case doctor would be the one to write down the patient's information, but the patient's information was not as important as the patient's treatment, and sometimes the doctor would look after the patient first and write his information down later.

Recording the patient's information one day late is not regarded as an error, especially in the field of mental-health treatment, because the symptoms were more sensitive and developed more slowly than with physical illnesses, and the doctor might have to wait longer to gather the patient's information, he said.

Students and parents are still keeping their faith in Prakitpao's Applied Physics school, registering for the May courses, and many said they did not believe their instructor was mentally ill.

"Dr Prakitpao is a good man, and I won't move my kids to another place," said Supinya Saibua, whose three daughters are studying at the tutorial school.

School staffer Patpong Limpaphan said that all courses were fully booked as before because the school had 10 courses that were taught via video and three courses by teachers in the classroom. The school has three teachers, including Prakitpao, so while he's away, the other two can take over his classes, Patpong said.