A gay man from the southern Russian city of Volgograd who was tortured to death in an apparent hate crime, was sexually assaulted with beer bottles, and had his skull “smashed with a stone”, authorities said on Sunday.

The death of the man has concerned activists, who say prejudice is becoming more concentrated due to anti-gay laws.

The naked and beaten body of the 23-year-old man was found in the courtyard of an apartment building in the city on Friday morning, a spokeswoman for regional investigators told AFP.

The report suggests that he had suffered multiple injuries to his body, including to his genitals, and that he had been sexually assaulted with beer bottles.

“He was raped with beer bottles and had his skull smashed with a stone,” Natalia Kunitskaya, a spokeswoman for the Volgograd region branch of the Investigative Committee, told AFP.

She went on to admit that the attack was believed to have been a hate crime, which was noted as a rare admission from Russian law enforcement agencies on the issue of homophobia in the country.

A Saturday statement from the Moscow-based Investigative Committee confirmed that two men aged 22 and 27 had been detained in connection with the attack. One of the suspects has a criminal history, the statement said.

It went on to say that they thought the victim had been drinking with two men, apparently while celebrating Victory Day, a national holiday in Russia held on 9 May.

Regional Investigator Andrei Gapchenko, said the men started beating the victim when he told them he was gay.

Gay rights proponent Nikolai Alexeyev, a major figure in LGBT activism in Russia, said: “This monstrous incident in Volgograd demonstrates the fruits of the homophobic policy that is being conducted in this country, including the initiative to ban homosexual propaganda.”

In January the Russian State Duma adopted the first reading of a homophobic censorship bill which would impose federal sanctions for the promotion of “gay propaganda”, similar to those passed in several regions of Russia, including St Petersburg. 

In Australia in February, Carl Katter started a campaign urging Melbourne City Council to break off its cultural partnership with St Petersburg over laws banning the “promotion” of gay and trans identities to minors, enacted by the Russian city in February of last year.

Venice and Milan have already cut their ties with St Petersburg over the laws.

Russian President Vladimir Putin, in April confirmed reports that the country may change its agreements for the foreign adoption of Russian children, in the light of France legalising equal marriage, to prevent gay, married couples from adopting.