Police have picked up a female clerk believed to have masterminded a robbery at the Road Transport Department (RTD) office here in Jalan Genting Kelang, Setapak on July 4.

Kuala Lumpur police chief Datuk Amar Singh Ishar Singh said the 40-year-old woman was believed to be the 'insider' who planned the 'robbery' involving losses of RM754,000 in cash and several cheques amounting RM444,000 in the 5.40pm incident.

"We have also detained eight other individuals (including) a woman, six men and an Indonesian man, all aged between 24 and 67 in connection to the case and retrieved cash of RM111,000 and jewellery worth about RM5,000 from those detained," he told a press conference here Thursday.

Amar Singh said the police were now closing in on two other suspects believed to be involved in the robbery.

The case is being investigated under Section 395 and 397 of the Penal Code, he said.

On the day of the incident, two men in helmets, armed with a machete, walked into the office using back door which was unlocked and point the machete to a female worker before they took the cash from a counter at the Revenue Unit.

The police had subsequently set up a special task force with help from Bukit Aman Criminal Investigation Department to find the suspects.