Numerous drug trafficking suspects remain at large despite months of police crackdowns in Lufeng city, Guangdong province - home to the infamous "meth village" raided earlier this year.
Meth is the street name for methamphetamine, a powerful and highly addictive stimulant.
Liu Yuejin, head of the narcotics control bureau with the Ministry of Public Security, conceded on Thursday that investigations were hampered by the drug rings' sheer scale and the fact some officials offered protection.
"There are many people involved … and we cannot arrest them all in one operation," Liu said.
The narcotics chief said the syndicates' transnational reach also posed challenges.
Liu said drug trafficking in Lufeng, a base for drug-making since the 1990s, had eased more than a decade ago but resurfaced in recent years owing to funding from Southeast Asian syndicates and growing demand for illicit drugs.
Investigations were ongoing and suspects were still being sought, Liu said, without giving a number. He was speaking on the sidelines of a drug prevention meeting in Beijing that included representatives from the United Nations and five Southeast Asian countries.
Lufeng's Boshe village achieved international notoriety after three tonnes of meth were seized and 182 drug suspects were arrested in a pre-dawn police raid on January 2.
Villagers armed with automatic weapons and grenades resisted the police raid in January. It was estimated that one-fifth of households in the village were involved in the trade.
The 182 suspects allegedly belonged to 18 production and trafficking rings based in and around the village.
Among them were Boshe's Communist Party chief Cai Dongjia, and 13 other village officials and local police chiefs.