Over 90 per cent of food traders in the country use illegally recycled cooking oil to save costs, reported Harian Metro.
Malaysian Muslim Consumers Association (PPIM) chief activist Datuk Nadzim Johan said that many complaints had been lodged over the matter.
"The practice is worrying as the use of low-quality oil can lead to lung, heart and liver diseases.
"Used or recycled cooking oil should only be utilised by the biodiesel industry, not by the food industry," said Nadzim.
He added that there have been many sightings of pasar malam traders using recycled cooking oil.
PPIM is currently collaborating with the appropriate agencies to investigate the validity of the claims.
Fomca communications director Mohd Yusof Abdul Rahman said that it has also received complaints from the public about the matter.
Yusof said that Fomca had informed the Health Ministry about the complaints but the ministry claimed that it has not found any concrete evidence to show that food traders were using recycled oil.
Yusof said that the matter should be taken seriously as recycled cooking oil taken from non-halal food premises should not be used by halal food premises.