Russian investigators say they are examining allegations that law enforcement officers tortured a Kyrgyz citizen who was detained in the wake of an explosion that brought down part of an apartment building in the city of Magnitogorsk, killing at least 39 people.
The chief prosecutor in the Chelyabinsk region, Vitaly Lopin, told reporters on January 29 that police had provided investigators with all the information they have on the allegations that Khusnidin Zainabidinov was tortured while in custody earlier in January.
Lopin asserted that Zainabidinov and his wife, Khalimakhon, had "retracted their previous statements and fully deny any violence by police."
But Lopin also said that there were traces of violence on Zainabidinov's body, and Khalimakhon Zainabidinova denied she had retracted her initial statement.
In comments to the independent newspaper Novaya Gazeta, she stressed that she had said her husband was tortured by Federal Security Service (FSB) officers, not police, and that she had no communication with the Chelyabinsk regional prosecutor's office.
Zainabidinova told the newspaper her husband told her that FSB officers tortured him, using electric shocks, before handing him over to the local police.
Zainabidinova told RFE/RL last week that Zainabidinov, 29, was tortured by security officers for six hours on January 16.
Russian authorities say the most likely cause of the blast that destroyed a whole section of an apartment block in the city 1,400 kilometers southeast of Moscow on New Year's Eve was a gas leak.
After the extremist group Islamic State (IS) claimed responsibility for the explosion, the federal Investigative Committee said that no traces of explosives had been found in tests of material from the site.
But several Russian media reports following the building collapse suggested it could have been a terrorist attack.
The allegation that Zainabidinov was tortured added to those suspicions, because his wife said officers had accused him of involvement in the blast and questioned him about it.
She said her husband's interrogators demanded he "confess" to involvement into the blast and provide information about unfamiliar "bearded men" whose photos they showed him.
In a January 25 statement, the Russian Interior Ministry said that Zainabidinov was detained for possible extradition to Kyrgyzstan, where it said he was wanted for alleged involvement in unrest in June 2010.
It said police did not suspect him of involvement in the building collapse.
Several deadly apartment-building explosions in Russia in the past 25 years have been blamed on militants from the North Caucasus, where federal forces have fought two devastating wars against Chechen separatists and an Islamist insurgency stemming from the conflicts still simmers. Household gas blasts have also been blamed for many such disasters.