Millions of dollars worth of Malaysian military equipment has been stolen for sale on the black market, a report said Tuesday, after officials revealed two fighter jet engines had gone missing.

Attorney-general Abdul Gani Patail said two engines worth 29 million dollars had been taken from a military airbase.

The airforce reported the theft of the US-made Northrop F-5E jet engines in August last year.

Armed forces chief Azizan Ariffin said the theft was only the "tip of the iceberg" after an audit revealed millions of ringgit worth of equipment was missing, the New Straits Times reported.

Azizan said those found guilty of stealing and selling the engines should be charged with treason.

"Their act jeopardises national security. They are traitors and should be punished for treason," he said.

The newspaper said the stolen jet engines were sold to arms dealers on the black market abroad.

The end buyer of the stolen kit was not immediately clear, but a number of countries have fighters that use the engines.

Prime Minister Najib Razak Monday vowed there would be no cover-up in the investigation.

Police have arrested four individuals, including the buyer, the seller and airforce personnel who assisted in stealing the engine.