Police are investigating whether the food served on board the missing Malaysian airliner was poisoned.
They are also retracing every piece of cargo that was loaded on to the Boeing 777, including tons of purple mangosteen, a tropical Asian fruit with a leathery shell surrounding moist, fragrant snow-white flesh.
Malaysia's top police officer Khalid Abu Bakar said the plane's food caterers were being scrutinised in an investigation that has so far failed to uncover any significant leads into the disappearance of the plane with 239 people on board on March 8.
Inspector-General Khalid said every possible angle had to be investigated to rule out sabotage.
"For example when we knew there was a load of mangosteen on board we had to find out where the mangosteen came from," he said.
"We tracked down who plucked the fruits, who packed them and shipped them out, who put them on the plane."
Inspector-General Khalid said in China investigators tracked down who was buying the fruit and for how much.
"Imagine how many people we must interview and that was just the mangosteen," he said.
Police have refused to publicly release the plane's cargo manifest but it is known to include a consignment of lithium-ion batteries that have previously been blamed for causing fires on aircraft.
Malaysia Airlines claims the batteries are not dangerous en-flight as long as they are packed to international standards.
Meanwhile, Malaysia's ambassador in Kuala Lumpur, Hulang Huikang, has defended Malaysia's handling of the plane's disappearance, denying allegations of any cover-up.
"There were weaknesses in the co-ordination between different departments and contradictory statements were given," Hulang said.
"There need to be improved in future efforts. But in the face of such a rare and immense disaster, no-one can perform perfectly," he said.
Hulang accused Western media of playing a disgraceful role.
"They have published false news, stoked conflict and even spread rumours," he said.
"These could provoke the frail spirits of the next of kin and damage the good relations between Malaysia and China. We strongly oppose this."
- Fairfax Media