Two missing US-made fighter jet engines, worth RM100 million and stolen from a military airbase, have been traced to Argentina, police said today.

Police chief Musa Hasan said officers were checking with their counterparts in Buenos Aires to confirm if the missing engines are still in the country.

"The stolen engines have been taken to Argentina," the police chief told AFP . "We have to check if the engines are still in that country."

Musa told the Star newspaper that several top airforce officers, including generals, are expected to be questioned in connection with the theft.

Four people, including three low-ranking personnel, have already been arrested and freed on bail for their alleged role in the theft, he said according to the daily.

"We need to question all of them as it is not easy to just cart away the engines without authorisation and proper documents," he was quoted as saying.

'Tip of the iceberg'

The government is facing a storm of criticism over allegations of official corruption after the theft of the engines.

News reports this week said the two Northrop F-5E jet engines had been sold on the black market by military officers to a South American company after being taken from a military airbase, apparently last year.

Armed forces chief Azizan Ariffin said the theft was only the "tip of the iceberg" after a newly completed audit revealed equipment worth millions of ringgit was missing.

Besides the engines, military equipment including parts of the jet fighter were stolen.

A number of countries subject to US arms embargoes, including Iran, Sudan and Venezuela, have F-5 fighters that use the antiquated engines.

The jet first flew in 1963 and Northrop ended production in 1989.

"The government should declare it has failed in the fight against corruption. The country is heading in the direction of a failed state like Zimbabwe," prominent opposition lawmaker Tian Chua told AFP .

"The theft could not have happened without the sanction of top officials," he said.

Defence expenditure used as kickbacks

Prime Minister Najib Razak has vowed a full and open investigation.

But Tian said that under Najib's leadership, national wealth was being plundered and that "defence expenditure is used for kickbacks to government cronies".

"In return, they provide political funding to the ruling politicians to remain in power," the outspoken lawmaker added.

The opposition claims that an illegal commission of RM540 million was paid to a close associate of Najib to help broker the purchase of two French-made submarines.

The prime minister has denied there was any wrongdoing in the deal, which was signed in 2002 when he was defence minister.

Khalid Samad, a PAS lawmaker, said the latest scandal showed it was "business as usual" for Najib.

"So many parties must be involved in getting the engines out of the country. It is scary," he said.