Dutch foreign minister Frans Timmermans has described the imprisonment of Russian opposition leader Alexei Navalny on embezzlement charges as worrying, Nos television reports.

Navalny was jailed for five years on Thursday for leading a gang which allegedly stole money from a timber firm. He has always maintained his innocence, saying the charges were politically motivated.

‘Throughout the trial there was no evidence to underpin the claims of corruption,’ Timmermans said. Given the verdict, there is every reason to be concerned about the justice system in Russia, he said.

Timmermans also called on the people of Russia to continue their efforts to combat corruption.

A spokesperson for the EU’s top foreign policy official, Catherine Ashton, said the embezzlement charges were unsubstantiated, and that Navalny’s jailing posed ‘serious questions as to the state of the rule of law in Russia’, the BBC reported.