Senior prison officials at the Arctic penal colony where the Russian opposition figure Alexei Navalny was detained and died will be banned from the UK and have their assets frozen, under sanctions announced by David Cameron. The UK foreign secretary imposed sanctions on six individuals in response to Navalny’s death, which has been widely blamed on the Kremlin. The head of the penal colony, Vadim Konstantinovich Kalinin, who allegedly oversaw the brutal prison camp, is among those hit by the new restrictions. The Foreign Office said the six had been targeted for “activity that violates the right not to be subjected to cruel, inhuman or degrading treatment or punishment and the right to life”. Announcing the sanctions, Cameron said: “It’s clear that the Russian authorities saw Navalny as a threat and they tried repeatedly to silence him. FSB operatives poisoned him with novichok in 2020, they imprisoned him for peaceful political activities, and they sent him to an Arctic penal colony. “No one should doubt the oppressive nature of the Russian system. That’s why we’re today sanctioning the most senior prison officials responsible for his custody in the penal colony where he spent his final months. “Those responsible for Navalny’s brutal treatment should be under no illusion – we will hold them accountable.” Rishi Sunak also confirmed the sanctions as he appeared in the House of Commons for prime minister’s questions. “He died for a cause to which he dedicated his whole life: freedom,” Sunak told parliament. “And to return home knowing that Putin had already tried to have him killed was one of the most courageous acts of our time. “Together with our allies we are considering all options to hold Russia and Putin to account and this morning we sanctioned those running the prison where Alexei Navalny’s body still lies.” In response, the Labour leader, Keir Starmer, said Navalny had “died to expose the corruption of the Putin regime”, adding that it was a reminder that Russian president Vladimir Putin has “stolen not just the wealth but the future and democracy of the Russian people”.