Fresh illicit drugs are surfacing on the European Union market at a rate of almost one a week, the European Monitoring Centre for Drugs and Drug Addiction (EMCDDA) conveyed on Thursday.
In 2011, a record 49 new drugs were identified, up from 41 reported in 2010, the largest number of new substances ever reported.
The Lisbon-based centre attributed the increase in the number of new drugs -- mostly synthetic cannabinoids and synthetic cathinones -- to the fact they could easily be obtained over the internet.
"We now see new drugs marketed in attractive packages on the internet or sold in nightclubs and on street corners," said EMCDDA Director Wolfgang Goetz.
"Whatever the source, the simple fact is that a dangerous game of roulette is being played by those who consume an ever-growing variety of powders, pills and mixtures, without accurate knowledge of what substances they contain and the potential health risks they may pose," he said.
The number of online shops offering at least one psychoactive substance or product more than doubled from 314 in January 2011 to 690 in January 2012, the centre said in its report.
"The selling of illicit drugs and new psychoactive substances is yet another area where the internet is abused by organised criminals," European Police Office (EUROPOL) director Rob Wainwright said in a statement.
"We must ensure that law enforcement agencies have the modern operational and legislative tools to combat such cases effectively," he added.
A 2011 Eurobarometer survey of young people showed that some 5 percent of respondents aged between 15 and 24 said they had used 'legal highs'.
These substances were mainly obtained through friends (54 percent), at parties or in clubs (37 percent), in specialised shops (33 percent) or over the Internet (7 percent), the report said.