The Malaysian Anti-Corruption Commission (MACC) has not ruled out making more arrests in relation to illegal bauxite mining in Pahang.

The commission's director of investigation Azam Baki said this involved several individuals suspected of being the middlemen in protecting the activities.

"We don't discount that more suspects would be arrested to facilitate investigations in relation to yesterday's case based on the information we have received.

"Our officers are now tracking other individuals, including the middlemen," he told BNBBC.my , the official website of the BN Backbenchers Club.

Yesterday, the anti-graft agency revealed it had detained four Land and Mines Office (PTG) employees, including a senior officer.

The four were suspected of requesting and receiving bribes from unlicensed bauxite miners in exchange of protecting them from enforcement officers.

In a Twitter posting, former information minister Zainuddin Maidin asked if MACC is only targetting the " ikan bilis " (anchovies).

"When the four PTG employees were detained because of the bauxite issue, many asked if the state exco is not involved in the approval of this project? Only the ' ikan bilis '?" he said.

Bila4pegawai PTG ditahan SPRM kerana isu bauksit,ramai tertanya apakah EXCO negeri tak terlibat dlm kelulusan projek ini.Ikan bilis shj?

— Zainudin Maidin (@ZainudinMaidin) January 7, 2016

Meanwhile, Azam denied MACC made the arrest only after the federal government announced the three-month moratorium on bauxite mining.

He described this as a mere coincidence.

MACC had been actively investigating the element of corruption since the middle of last year and moved in after obtaining clear information.

Azam said the commission would only make arrests when it has sufficient information.

"It is only a coincidence the arrests took place when the moratorium was announced," he added.

The MACC director also urged the public to inform the commission of any bribery cases in their respective areas.

"If people do not provide us with information, we wouldn't know and cannot investigate. Don't be afraid to give us information, we will protect all the information," he said.