AN AVIATION expert has suggested a “sinister” possible cause of the catastrophic South Korean aeroplane crash that killed 179 people.

Meanwhile, police have raided the airport where the plane crashed, the office of the airline and several other locations as part of the investigation into the disaster.

Speaking on Australia’s “Today” show, aviation expert Professor Ron Batsch said something more “sinister” than the current theories could be behind the crash.

He said he believes it is “pretty unlikely that a birdstrike alone would be sufficient to bring down an aircraft or to foresee landing gear not to be able to be operative”.

Bartsch added that the pilot would have known about the high risk of landing, particularly without reverse thrust or flaps available to slow the aircraft down.

“So it may have been, and this is only speculation, that there may have been something more sinister on board the aircraft that could have caused it,” he told the programme.

It is still unclear exactly what happened in the moments before the plane attempted touch-down without landing gear and skidded along the runway into a wall.

All but two of the 181 on-board the plane were killed after it crashed into a concrete wall and burst into flames.

The leading theory so far has been that a bird struck one of its engines.

Kim Yi-bae, CEO of the airline, Jeju, told reporters that “Nothing abnormal was noted with the landing gear.”

He said that a standard pre-flight inspection found “no issues” at all with the passenger plane before it crashed.

“As for whether the landing gear functioned properly, that is directly related to the accident investigation, and we are not in a position to know at this time,” he told a press conference in Seoul.

However, South Korean police have banned Yi-bae from leaving the country whilst the investigation continues.

On Thursday police acted on multiple warrants granted on charges of professional negligence resulting in death.

They searched various locations including Maun International Airport and the Seoul office of Jeju Airline.

Bosses of the South Korean airline allegedly knew that the concrete wall it smashed into was too close to the runway.

Comments in the airport’s operating manual – uploaded early this year – said the embankment was too close to the end of the runway.

It recommended that the equipment location be reviewed during a planned expansion project at the airport, Reuters reports.

It recently emerged that the Boeing 737-800 completed a whopping 13 flights in the 48-hour period before it crashed, travelling to five different international destinations.

Industry experts have raised concerns about whether the Boeing plane over extended itself by scheduling too many flights during the peak holiday season.

It was used for a journey between Maun, Jeju Island and Incheon, which is west of Seoul, South Korean news agency Yonhap reported.

It also travelled to Beijing, Bangkok, Kota Kinabalu, Nagasaki and Taipei.

The official investigation into the cause of the crash is expected to take months as the jet’s flight data and cockpit voice recorders are analysed.

The plane had two black boxes on-board, which record flight data including cock-pit audio and could help to determine the cause of the crash.

One of the boxes was damaged in the crash and will be sent to the US for analysis because South Korea does not have the technology required to extract the data.