Image copyright Science Photo Library Image caption Customs officers found parcels bound for abroad containing white powder

A chemistry professor has been arrested in China accused of making psychoactive drugs that were sold to the UK, Canada, the United States and Australia.

Police said he sold at least 193kg (30 stone) of methylone last year after discovering a gap in the market when he went to Australia as a visiting professor, Xinhua news agency reported.

Seven others were arrested in connection with the raid in Wuhan.

It follows the arrest of a Xian professor for making illegal drugs.

Xinhua reported in May that that professor, with the surname Lu, had been arrested and dubbed China's real-life Walter White after the Breaking Bad character.

It is not clear whether the cases are linked.

The professor arrested in Wuhan, whose surname is Zhang, started a company in 2005 which ostensibly produced medical coating and solvent, Xinhua reported.

Police said he "found while acting as a visiting academic in Australia that some psychoactive drugs were in heavy demand, but hard to find there. He decided to make those drugs when he got back to China for profit".

He recruited people to produce "hundreds of kilograms" of drugs and sold them overseas through mail order, police said.

In November last year, customs officers found at least nine parcels bound for abroad which contained the stimulant methylone, commonly used as a substitute for MDMA, or ecstasy.

On 17 June customs and police raided Mr Zhang's lab in the Jiangxia district of Wuhan. About 20kg (3 stone) of drugs were seized.