JAKARTA, Indonesia—The stall warning of AirAsia Flight 8501 could be heard going off on the cockpit voice recorder, a crash investigator said Wednesday.

“The warning [alarms] kept on screaming, and in the background, they [the pilot and co-pilot] were trying to recover the plane,” said the crash investigator. “But what they said wasn’t clear,” the investigator said.

He added that the flight data recorder also showed the stall warnings were going off.

The investigator’s comments followed a description by Transport Minister Ignasius Jonan on Tuesday that the plane, which crashed on Dec. 28, stalled after climbing at a rate beyond the normal limit.

The Airbus A320 jet turned away from its assigned flight path en route from Surabaya to Singapore, climbed at a rate of more than 8,000 feet a minute—six to eight times the normal rate—then descended and lost contact within three minutes, Mr. Jonan said, citing data from the plane’s automatic dependent surveillance-broadcast, or ADS-B, system.