It has been described as the biggest cash haul in history, and a source familiar with the case revealed that Malaysian Anti-Corruption Commission (MACC) officers conducted three months of intelligence work before moving in.

"This is the result of a joint operation mounted by MACC in Sabah and also the Putrajaya headquarters," the source told Malaysiakini on condition of anonymity.

The source also disclosed that investigations are being carried out to determine if the suspects, one of whom is believed to be a member of a political party, detained on Tuesday are linked to politicians in the state.

The pair are the director and deputy director of a Sabah public utilities company. The deputy director’s brother, who is said to be a 'Datuk', and an accountant were also arrested.

A raid on the houses and their office saw MACC officers retrieving RM53 million in cash.

Also seized were nine cars including a Range Rover, Audi, BMW, Ford Ranger, Mercedes Benz, Mazda, BMW, Lexus, and Volvo.

The officers also confiscated branded watches, 127 land grants and 94 handbags from the wives of the suspects as well as the items in deposit boxes.

MACC has obtained a seven-day remand order against the suspects since Wednesday.

To a question on whether the Sabah sting was the largest haul in terms of cash, the source said it was, but pointed out that the biggest sum involving a MACC investigation is related to 1MDB and SRC International Sdn Bhd.

"That certainly involved a bigger sum," added the source.

Overall, the seizures totalled to about RM114 million.