A Singaporean and two Malaysians were charged on March 24 over the dumping of chemicals into Sungai Kim Kim -- a Pasir Gudang river.

Johor police are also looking for another Singaporean to assist in the ongoing investigations.

Three men charged

According to The Star, two of the men who were charged were directors of a used tyre-processing company -- Singaporean Wang Jin Chao, 34, and Malaysian Yap Yoke Liang, 36.

The third man was a Malaysian lorry driver, N. Maridass, 35.

Maridass has been accused of illegally disposing of chemicals into Sungai Kim Kim, while the two directors are accused of conspiring with Maridass.

All three men pleaded not guilty to the charges.

One Singaporean still wanted

According to Channel NewsAsia, the Singaporean man still wanted for questioning has been identified as 49-year-old Sim Wei Dee.

He is also a registered director of the used tyre-processing company.

A statement provided to CNA by the Singapore Police Force said that it had been in touch with the Royal Malaysia Police and were waiting for an official request for assistance in regards to the arrest of Sim.

Police respond to public criticism

A total of eight individuals have been released on police bail after investigations revealed that they were not involved in the case.

The Malaysian police has also dismissed allegations that the police probe into the case is just a diversion for the public.

Effects of dumping

It was reported that more than 4,000 people have been affected and 111 schools closed following the chemical waste incident at the river on March 7.

Top image screenshots from The Star Online YouTube