Johor police chief Ayob Khan Mydin Pitchay said police had noticed this trend in recent months and were now more vigilant.

Khan spoke to reporters after giving details on a raid on a drug processing laboratory in Desa Cemerlang, Seri Alam, on Sunday.

Drugs, equipment, vehicles and jewellery worth RM6.4 million were seized.

Khan said police arrested six men, aged 34 to 48, including a member of Geng 21.

He said the discovery of the lab producing ketamine followed a fire reported at a factory.

He said police seized 30kg of ketamine worth RM1.65 million, 100 litres of liquid suspected to contain drugs worth RM3.3 million and 2kg of suspected drug powder worth RM110,000.

The drugs could have supplied 660,000 drug addicts, Khan said.

Also seized were precursor chemicals, drug processing machines and equipment, as well as six cars and jewellery, all worth RM1.34 million. Five bank accounts had been frozen for police investigations.

Khan said police were tracking down five more suspects, comprising four Malaysian men, including the head of the syndicate, and a Malaysian woman.