India, Aug. 13 -- The commander of the Air India Phuket-Delhi flight that lost altitude suddenly on August 4, injuring several passengers, told investigators he had been struggling with sleep and was on medication prescribed by his family doctor, two people familiar with his account to the Aircraft Accident Investigation Bureau (AAIB) said. They spoke on condition of anonymity and described more than an hour of questioning by investigators.

The disclosure comes a day after it emerged the pilot's preliminary post-flight drug test was recorded as "non-negative," a screening result indicating a sample flagged for further analysis, and that his confirmatory test came back positive for cannabis.

The pilot told investigators he had been unabl...