India, Sept. 4 -- A preliminary report in the turbulence incident on an Air India flight from Phuket to Delhi has revealed that the pilot tested positive for psycho-active substance. The Hindustan Times had earlier reported about the pilot testing positive for drugs.

"The confirmation of use of psycho-active substance is a serious concern and AAIB recommends appropriate actions by DGCA on priority," the report said.

A detailed investigation in the matter is underway. The final report will be published in due course, it said.

On August 4, flight AI2379 from Phuket to Delhi dropped 300 feet in a sudden loss of altitude during cruise, injuring 20 passengers and four crew members.

An initial statement from Air India had cited turbulence a...