LONDON (Reuters) -The British government said on Friday it was summoning the Russian embassy to make clear it held Russian authorities "fully responsible" for the death of opposition leader Alexei Navalny.
The foreign ministry said in a statement that Navalny's death at an Arctic penal colony "must be investigated fully and transparently."
British foreign minister David Cameron had said earlier on Friday that Russian President Vladimir Putin should answer for Navalny's death.
"We should hold Putin accountable for this," Cameron said, speaking to reporters in Munich where he was attending a security conference.
"There should be consequences, because there's no doubt in my mind, this man was a brave fighter against corruption, for justice, for democracy."
British Prime Minister Rishi Sunak also paid tribute to Navalny, calling him "the fiercest advocate for Russian democracy."
Navalny, Russia's most prominent opposition leader, collapsed and died on Friday after a walk at the "Polar Wolf" penal colony where he was serving a long jail term, the Russian prison service said.