Missing Malaysia Airlines Flight MH370 mystery continues to disappoint the investigators and loved-ones of the victims. Reports claimed Boeing 777 that went missing more than 3 weeks ago may never be recovered.

Sydney Morning Herald cited the air chief marshal leading the probe of the missing Malaysian Flight MH370 has raised doubts about finding the jet that was lost more than 3 weeks back.

While speaking to the media on Tuesday, Air Chief Marshal Angus Houstan said the disappearance of HMAS Sydney and expressed the high probability of not resolving the MH370 mystery. It took 60 years to locate HMAS Sydney which disappeared during the time of WWII and was found only in 2008.

MH370 disappeared on March 8, 2014 with 239 passengers on board with no traces of the plane or its debris. The plane was believed to have crashed in Indian Ocean, killing all the passengers on board.

"We have a starting point and we need to pursue the search with vigor and we need to do that for some time to come," Air Chief Houstan noted.

He claimed the authorities know little about the altitude and the speed that the aircraft traveled. The investigation of the missing Malaysia Airlines flight is "by far the most challenging he had come across."

Angus Houstan is a former Air Force chief. He has been a part of several missions serving as search and rescue helicopter pilot.

Even with the advanced technology, they are "working from a very uncertain starting point," the air chief marshal said.

"There were eye witnesses who saw the ship disappear over the horizon but it took us about 60 years to find HMAS Sydney on the bottom of the ocean," he added while comparing the two incidents.

Meanwhile, Malaysia's Police Chief Khalid Abu Bakar hinted the possibility of never determining the true cause of the disappearance of Malaysia Airlines Flight MH370, according to Guardian.

In a brief in Kuala Lumpur, he said the investigation "may go on and on and on."

While addressing the people, he suggested them to be patient and raised the possibility of not knowing the "real reason behind this incident," if the investigation will not be thoroughly conducted.

The plane vanished while traveling to Beijing from Kuala Lumpur. It is reported the plane's transponder was turned off making it undetected by the radar.

So far the investigation has led to several theories. Crew and passengers' also came under investigators' scrutiny.

According to the latest update, the investigators are now checking upon the cargo and food that were served to the passengers before eliminating the chances of food poisoning.