Dutch prime minister Mark Rutte has named the death of Russian activist Alexei Navalny in a Siberian prison as terrible news which “once again bears witness to the immense brutality of the Russian regime”. 

Navalny, 47, one of Vladimir Putin’s most high profile critics, was being held in a jail under a “special regime” after being given a 19 year jail term. The prison service said in a statement on Friday he had “felt unwell after a walk and almost immediately lost consciousness”. He was then confirmed dead by paramedics.

Navalny, Rutte said, was a man who strived for democracy and against corruption, adding that he would hold Russia responsible for his death.

“This Russia is prepared to go as far as it can. The man did nothing other than campaign for democracy, freedom, the rule of law and free press in Russia, using peaceful methods, so that there would be a normal, functioning society.”

Rutte said he had met Navalny and found him to be a driven man. “He was also critical of the west, asking if we were doing enough,” Rutte said. 

Rutte’s comments were echoed by many MPs, with far right leader Geert Wilders saying Navalny “died in a barbaric penal colony run by a barbaric regime”.

GroenLinks-PvdA leader Frans Timmermans said Putin’s regime had claimed yet another victim, while VVD leader Dilan Yesilgöz praised Navalny’s courage. “His struggle is and remains our struggle,” she said. 

Dutch foreign minister Hanke Bruins Slot said news of his death is shocking. “He campaigned against corruption and for democracy in Russia, and now he has paid for that with his life.”

He was one of the few opposition leaders in Russia who dared to stand up to Putin, she said. She also stressed that the international community had spoken out against his imprisonment and the lack of medical care he received in jail.