The knock on the door came at 7.30am and the brutal interrogation lasted for almost eight hours. After being taken from his home in Crimea to a police station, Weldar Shukurdiyev was threatened and assaulted.

“Two men were beating me,” he remembered. “There were constant threats: they said they would make me eat the Ukrainian flag. Every five minutes somebody would enter and shout more insults.”

Mr Shukurdiyev is a Crimean Tatar, one of the original inhabitants of the Black Sea peninsula. Two years after Russia seized their historic homeland from Ukraine, the Tatars are now the target of an escalating campaign of repression mounted by their new overlords.

The suspicion of them is based on a painful truth: no-one has a more viscerally powerful reason to oppose the return of Russian rule over Crimea than the Tatars. Like most of his brethren, Mr Shukurdiyev was born not in Crimea, but in what was then the Soviet Republic of Uzbekistan.

His father was among 210,000 Tatars deported from Crimea in the penultimate year of the Second World War. In the space of three days from 18 May 1944, every last Tatar – man, woman and child – was rounded up in towns and villages across Crimea and herded onto sealed trains, which transported them for 2,000 miles to the barren steppe of Uzbekistan.