Psychiatrists were refusing to allow police to question the 28-year-old "net idol" whose luxury car crashed into eight other vehicles, injuring several people, in inner Bangkok on Tuesday.
Pol Capt Papinawit Senaplaeng, deputy chief interogator at Huai Kwang police station, said the psychiatric department of Ratchaburi Hospital in Ratchaburi province did not permit investigators to question Kritrada "Namzom Zomy" Tabtimphol on Thursday.
They said the woman was suffering from hysterics. She was unable to control herself and interrogation would worsen her condition.
Police have brought a preliminary charge of reckless driving causing property damage and injury against her. Any other charges would have to wait until she had been questioned, Pol Capt Papinwat said.
He said investigators had finished questioning eight people damaged in the incident, and were awaiting results of tests for chemical or addictive substances in Ms Kritrada's blood sample. Ratchaburi Hospital was doing the tests.
Police found anti-depressant and anti-seizure medications in her BMW car after the crash, he said. The high-speed accident happened on Ratchadaphisek Road near Rama IX intersection during the Tuesday evening rush hours.