Chinese and Australian police have arrested nine suspects and confiscated 3.35 tonnes of a key component of ecstacy in a major drug chemical smuggling case.

Some 2.7 million ecstasy pills with a street value of 550 million yuan (86.4 million U.S. dollars) could have been made with the amount of safrole seized, according to a statement released on Monday by China's Ministry of Public Security.

The case dates back to a period between April and August last year, when Australian customs officials discovered three batches of safrole oil, which weighed 2,849 kg in total. The packages were smuggled out of China labelled as items including combs and hair clips, according to the ministry.

Based on information from the Australian side, police in central China's Henan province in April seized six suspects thought to have bought three tonnes of illegally extracted safrole and sent some of the oil to Australia in shampoo bottles. The rest was kept in the southern Chinese city of Guangzhou, said the statement.

It quoted an unnamed official as saying, "During the investigation, Chinese police and Australian Federal Police maintained close cooperation and high mutual respect and trust in exchange of case information and evidence."

The official said the bust showed Chinese police's "firm standpoint and positive attitude" toward international anti-drug cooperation.