The 85 arrested suspects involved in allegedly the largest drug-making case in China are under trial, a spokeswoman of the State Food and Drug Administration said Tuesday.

Spokeswoman Yan Jiangying told a regular press conference that China would further tighten control on drug precursors as the case involved ephedrine, a precursor to making ice that is also used in regular medicines for cough and cold.

"Their licenses would be revoked if they cause the direct flow of ephedrine-contained medicines to illegal channels," she said. "Those violating the criminal law would be handed over to police."

Chinese police had busted five drug-making gangs and smashed eight illegal drug processing factories nationwide that were involved in the case, confiscating 415 kg of ephedrine.

Police also confiscated 10 apartments, 21 vehicles, three pistols and 10 bullets illegally possessed by the suspects.

Yan said the lawless turned to illegally obtaining ephedrine-contained medicines through registered pharmaceutical companies as controls on the production and sales of ephedrine itself had been strict.

Since 2007, China has already tightened control on ephedrine-contained medicines, imposing limits on purchases at one time and prohibition of transactions in cash.