A son of ousted Ukrainian President Viktor Yanukovych drowned after a minivan he was driving plunged through the ice of Siberia's Lake Baikal, an aide to Ukrainian Interior Minister Arsen Avakov said.
Authorities in Russia, where Yanukovych has lived with most of his family since his ouster, did not immediately confirm the death.
But Avakov aide Anton Herashchenko said Sunday on Facebook that Yanukovych's younger son, also named Viktor, had died on Sunday in Lake Baikal.
The vehicle broke through the ice and tipped over onto the driver's side. Five passengers survived and "four of them didn't even get their feet wet," Herashchenko said.
Yanukovych Jr., 33, a racing car enthusiast who headed the Ukrainian Automobile Association when his father was in power, was not able to unbuckle his seat belt in time to get out, Herashchenko added.
Nestor Shufrych, a Ukrainian parliament deputy from the Opposition Bloc and a former ally of Yanukovych, gave a similar account on Facebook.
"He died the way he lived: behind the wheel of a car," Shufrych wrote.
Yanukovych Jr. had also been a deputy in the Ukrainian parliament as a member of the Party of Regions in which his father also served. The party released a statement on Monday expressing condolences to the deceased’s parents, his wife Olga and son Ilya.
In Moscow the Kremlin declined to comment. "I do not have any information on the subject," said President Vladimir Putin's spokesman, Dmitry Peskov. "I can neither deny nor confirm."
The Ukrainian Foreign Ministry said Monday that its Russian counterpart had yet to notify it about the death, the Interfax news agency reported.
Russian officials on Saturday provided an account of a drowning incident at Lake Baikal that did not match that of Ukrainian officials.
The regional branch of the Interior Ministry said in a statement Saturday that a vehicle with six passengers had fallen into the lake on Friday night. One of the vehicle's occupants died, but five survived, it said.
According to an undisclosed source in the Emergency Situations Ministry who was cited by Interfax, the victim was a local resident named Viktor Davydov.
Another undisclosed source cited by the RBC news agency claimed that Yanukovych Jr. had been living in the area under the last name "Davydov," his grandmother's maiden name.
Yanukovych Jr. was among the individuals sanctioned by the European Union over the crisis in Ukraine.
Sensationalist Russian television network LifeNews, which has good contacts among Russia's law enforcement authorities, quoted sources as saying the deceased's body was being flown by charter flight to the Black Sea peninsula of Crimea for burial.
Russia annexed Crimea from Ukraine last March. The Yanukovych family is known to have owned several properties in the region.
The deceased's father was ousted from the Ukrainian presidency in February 2014 after months of street protests sparked by his reluctance to sign an association agreement with the European Union.