Four policemen, who were hospitalised after inspecting 15 drums of chemicals at an oil palm plantation in Karak, Bentong, Thursday, are reported to be in stable condition.

Pahang police chief Datuk Abd Jalil Hassan said, however, the doctors were still monitoring them closely.

"One of the police personnel involved is also understood to be in the hospital for some time, as his antibodies are quite weak," he said when contacted today.

Abdul Jalil said four other personnel who were also affected in the incident and received outpatient treatment, were still on leave to make sure they were fully recovered before returning to work

He said the eight police personnel, who were at the scene, complained of suffering from headache and nausea, shortly after being on-site, believed to have been due to inhaling the chemical vapours.

He said all the personnel had requested permission to leave the site following the arrival of the Department of Environment and Hazardous Materials Division of the Malaysian Fire and Rescue Department.

"They also sought the permission of their superiors to be discharged from work earlier, but as a precaution, the superiors directed them to go to a health clinic, after which four of them were admitted to the Bentong Hospital," he said.

Abd Jalil said the police were investigating the origin of the chemical, believed to be sodium cyanide in solid form, which is commonly used in gold mining activities.

"We are looking at whether there are criminal elements involved, if the chemical was stolen from a nearby mine or elsewhere, to be sold to other miners nearby," he said, adding that the drums may also have been left there for disposal purposes as there were costs involved in disposing of them legally in a specific location in Negeri Sembilan.

Yesterday, Health Minister Datuk Seri Dr Dzulkefly Ahmad confirmed that four policemen had been hospitalised, while four others had received outpatient treatment after they complained of feeling ill following the inspection at the scene.

- Bernama