Environment Department director-general Norlin Jaafar said the waste had not only polluted the river but could also cause an outbreak of infectious diseases in the local community.

“We suspect a clinic near to the riverbank (is responsible for the waste) and I have directed Selangor DoE to take the evidence to the Chemistry Department for investigation so that action can be taken against the offender,” she said.

Offenders can be punished with up to five years’ imprisonment and fine not exceeding RM500,000.

Environment and Water Ministry secretary-general Zaini Ujang said the gotong-royong event involved the manual construction of a 1.4km trail to control river pollution.

“The gotong-royong involved 250 participants at a gazetted river area, thus bringing the community closer to the water source and to monitor the river ecosystem more effectively.