JAKARTA (AFP) - Indonesia will release the final report on last year's AirAsia plane crash by August, the transport minister told AFP this week.

The Airbus 320-200 went down in the Java Sea on Dec 28 in stormy weather with 162 people on board, during what was supposed to be a short trip from the Indonesian city of Surabaya to Singapore.

"(The NTSC) promised (the final report) will be released by August," transport minister Ignasius Jonan told AFP in an interview, referring to the National Transportation Safety Committee which is conducting the investigation.

The NTSC reports to the president and coordinates with the transport ministry.

Mr Jonan said that the parties involved in the investigation, including plane manufacturer Airbus and AirAsia, must accept the committee's findings and not interfere in the inquiry. "I have instructed the NTSC that the report must be as independent as possible," he said.

ICAO has stated the investigation should aim at preventing future accidents, not apportioning blame or liability.

The minister refused to reveal anything further about the investigation, pending publication of the final report.

The NTSC has so far shed little light on what caused QZ8501 to crash, or what occurred in the moments before the tragedy.

The committee has confirmed French co-pilot Remi Plesel was flying the plane, not former fighter jet pilot Captain Iriyanto.

It also found the plane climbed from 32,000 ft to well above 37,000 ft in 30 seconds, likely in an attempt to avoid a menacing storm. It then quickly turned to 32,000 ft before "gradually" descending towards the sea.

So far more than 100 bodies or body parts have been recovered from the sea.

Under International Civil Aviation Organization (ICAO) guidelines, the state conducting the investigation should release a final report within a year of the accident.