“In May 2007, drug police brought me to court and introduced me as a drugs baron, from whom – as they put it – they confiscated 56 tonnes of drugs,” he said. “It's ridiculous. The poppy seeds were solely intended for food, they had the tiniest amount of impurities – 0.1 percent – which perfectly fits into our state standards.”

Impurities are the key here. It is not the poppy seeds themselves that can get you high, it's the poppy straw – often present in large shipments – which can be used to extract opiates.

Experts say you can not have poppy seeds which are 100 percent pure, and a certain percentage of impurities is acceptable.

Meanwhile, the investigation into Roman's case is still ongoing, and if charged he could face up to 20 years in prison.

Many grocers across Russia have been accused of using the sale of poppy seeds as a cover for their drug business. Some are even calling for a ban on the import of poppy seeds to Russia.

All poppy seeds on Russia's food market are imported, because the cultivation of poppies here is prohibited.

Sergey Polyatykin, a doctor who specializes in drug addiction, says it is the customs service that drug police should start with – not retailers.

“The problem is that the seeds go through our customs and receive certificates and are not considered to be drugs. But when they get to retailers, drug police come along and say it is a drug, and launch a criminal case,” he said. “I think the import of poppy seeds should be stopped, at least for now.”

But Russia's drug police say it is the businessmen, not the customs service, who carry the full responsibility.

“They know perfectly well what they're doing by importing dirty poppy seeds,” said Vladimir Golubovsky of the drug police. “Only in 2008, over 550 000 people in Russia were registered as drug abusers – most of them are addicted to opiates. We just can't stand aside [and do nothing].”

However, some fear the drive to catch drug dealers can hit many unwitting grocers who buy poppy seeds for cakes and bread and end up behind bars.