Environment and water minister Tuan Ibrahim Tuan Mat said this brought the total number of arrests to nine, in addition to the four who were arrested earlier.
Results of the chemical analysis of the scheduled waste will be known in a week, he told reporters after visiting the scene this afternoon.
He said so far, nine men comprising five locals and four foreigners, aged between 30 and 50, had been detained to assist in the investigation.
Tuan Ibrahim said the source of the pollution was identified as a vehicle storage premises used by several companies.
“Through our investigation, we found that they used pipes from the trucks directly to the riverbank. We have obtained information and we will continue to search for the cause and identify the source of the incident.”
He stressed that his ministry would not compromise with those responsible and would monitor all with licences for scheduled waste disposal to carry it out in the proper way.
The case will be investigated under Section 345B of the Environmental Quality Act 1974 where offenders can be sentenced to a maximum mandatory jail term of five years and a fine of up to RM500,000.
Earlier today, Johor police chief Ayob Khan Mydin Pitchay said four local men including the premises owner were detained by the environment department (DoE) at about 11.30am not far from the scene.
He said following the incident, four women aged 24 to 49 were rushed to the Sultanah Aminah Hospital and Sultan Ismail Hospital due to shortness of breath.
“We will share the rest of the information later because the arrests have just been made. The police will provide full assistance to the DoE for follow-up operations, there may be more locations that we need to check on, and maybe more arrests that we need to make,” he told reporters after inspecting the situation at Kampung Baru Sri Aman.
Meanwhile, the state’s environment department director Mohd Famey Yusoff, who was met at the location, said samples had been taken from the contaminated area to determine the material causing the pollution.
“Currently, we aren’t sure what the discarded substance actually is. However, we have been able to identify the cause (but) we cannot disclose anything yet until it is confirmed via lab analysis.
“At this point, our officers and the police will raid the premises believed to be involved in illegal dumping activities,” he said.
In the meantime, he said round-the-clock surveillance would be carried out by the DoE to ensure the chemicals do not endanger residents in the surrounding area.