Russian President Dmitry Medvedev has signed into law a bill imposing tougher sentences on convicted members of organised criminal gangs, the Kremlin said in a statement on Tuesday.

The bill had already been approved by both houses of parliament in October, it said.

Tougher sentences will be handed out to gang members under the new law, ranging from 15 years to life in jail.

President Medvedev was quoted as saying by Russian news agencies that the law would "create a new legal framework to prosecute" those involved in organised crime as its widens the definition of criminal gang membership.

First Deputy Prosecutor General Alexander Bastrykin said authorities would now be able to pursue "the sponsors and coordinators" of criminal acts.

- For years, we have been unable to prosecute those who organise and coordinate criminal activity and now we have this opportunity - he said.