Tajikistan has asked Russia for an explanation after a Tajik man died while in the custody of Moscow police.
The father of Ilkhomuddin Shoev, who died at a police station in the Russian capital on November 21, told RFE/RL that his son appeared to have been badly beaten.
Tajik Interior Minister Ramazon Rahimzoda requested an explanation in a telegram to his Russian counterpart, Vladimir Kolokoltsev, that was posted on the Tajik ministry's website on November 28.
Rahimzoda also urged Kolokoltsev to personally oversee the investigation into Ilkhomuddin Shoev's death.
Moscow police have said that Shoev, a 38-year-old who was working in Moscow while his wife and children remained at home in Tajikistan, died of heart failure.
But his father, Sharofiddin Shoev, told RFE/RL that his son's body bore traces of a severe beating and violence.
Ilkhomuddin Shoev's body was repatriated on November 27, and he was buried the same day in his native village of Bakhoriston.
Moscow police spokesman Maksim Kolosvetov told RFE/RL earlier that an internal investigation had been launched into Shoev's death.
Many Tajiks work in Russia abroad and send money to their relatives in Tajikistan, the poorest former Soviet republic.
Relations with ethnic Russians and other natives of Russia are often tense, and there have been many allegations of police abuse of workers from Central Asia.