LONDON - A Russian pianist and anti-war activist has died in prison after going on hunger strike, his mother said, in what the European Union called a shocking case of political repression.

The death of Pavel Kushnir was first reported by a Russian news site last Friday and confirmed to independent outlet Mediazona on Monday by his mother, Irina Levina.

A Telegram channel with links to Russia's security services reported in May that Kushnir had been arrested and accused of inciting terrorist activity after posting anti-war material online.

Levina told Mediazona that an investigator from the FSB security service had told her that Kushnir died on July 28 while in pre-trial detention in Birobidzhan in Russia's far east.

It was not clear how long he had been on hunger strike. Levina said she had been told that he was hooked up to an intravenous drip "but apparently this was not enough" to save him.

Kushnir was an accomplished concert pianist who had studied at Moscow's Tchaikovsky conservatory.

EU external affairs spokesperson Peter Stano posted on X that the case was a "shocking reminder of (the) Kremlin's ongoing repression" and urged Russia to "respect its Constitution, release all prisoners of conscience & stop repression against anti-war protesters".

An independent Siberian politician, Svetlana Kaverzina, said Kushnir had been left isolated and without support because there was no local network of dissidents, and people had not known about his case.

"We couldn't chip in and send him a lawyer - we didn't know. We didn't write him letters of support - we didn't know. We didn't talk him out of sacrificing himself - we didn't know. He was alone," she wrote on Telegram.

Russia released eight dissidents from its penal colonies last week together with American ex-marine Paul Whelan and journalists Evan Gershkovich and Alsu Kurmasheva as part of the biggest prisoner swap with the West since the Cold War.

Human rights group Memorial says, however, that 333 people are still held as political prisoners in Russia, which has heightened a crackdown on dissent since launching its full-scale invasion of Ukraine in February 2022.

The Kremlin says Russia needs to uphold its laws to protect against threatening and subversive activity, which it frequently says is orchestrated by the West. It does not comment on individual cases, saying they are a matter for the courts and the prison service.

  - Reuters