The couple won the world championships in pairs figure skating in 1994, and U.S. media said they had lived in the United States since at least 1998, where they trained young ice skaters, Reuters reported.
Scores of people were feared dead after the American Airlines passenger jet carrying 64 people collided with a U.S. Army Black Hawk helicopter and plummeted into the frigid Potomac River near Reagan Washington National Airport.
U.S. Figure Skating, the governing body for the sport in the United States, said Shishkova and Naumov were reported to have been returning from a National Development Camp held in conjunction with the U.S. Figure Skating Championships in Kansas, and travelling with a group of young skaters.
Russia s Mash news outlet published a list of 13 skaters, many of them the children of Russian emigres to the United States, who it said may have been on the plane.
Speaking in St Petersburg, Ludmila Velikova, who trained Shishkova and Naumov when they were children and who was pivotal to their success, told Reuters that a group of 14 skaters and trainers had been on board the plane.
She said she was devastated by the loss of Shishkova and Naumov, but relieved that their son Maxim, who had competed in Kansas, had not been on the same plane.
THEY WERE MY CHILDREN
"They were my favourite sports people. They were part of my first attempt at the world championships and became champions in 1994. They were talented and beautiful people," said Velikova, visibly distraught.
"Apart from anything else they were my children. Zhenya (Shishkova) trained with me from the age of 11 and Vladik (Naumov) from age 14. They were like my own children. What s happened is awful. The best people have been taken away from us."
Inna Volyanskaya, a former skater who competed for the pre-1991 Soviet Union, was also reported to have been on board the plane, TASS said. She was a coach at the Washington figure skating club, according to its website.
The Kremlin expressed its condolences to the families of Russian citizens who lost their lives in the crash and said the news that Shishkova and Naumov had been on board appeared to be confirmed.
"There were other of our fellow citizens on board. It s bad news today from Washington. We are sorry and send our condolences to families and friends," Kremlin spokesman Dmitry Peskov told reporters.
Russia s figure skating federation voiced its condolences to those who had lost loved ones in the crash, but said it was unable to comment further.
"We are devastated by this unspeakable tragedy and hold the victims families closely in our hearts," U.S. Figure Skating said in a statement.
SKATERS HAD JUST COMPETED IN US CHAMPIONSHIPS
More than 180 athletes competed in the Jan. 20-26 championships in Kansas, the organisation said. The development camp was held Jan. 27-28 for nearly 150 up-and-coming skaters across performance levels, the U.S. Figure Skating website said.
The International Skating Union (ISU) said it was "deeply shocked by the tragic accident".
"We are heartbroken to learn that figure skaters, along with their families, friends, and coaches, are understood to be among those on board," the global governing body said in a statement. "Our thoughts are with everyone affected by this tragedy.
"Figure skating is more than a sport - it s a close-knit family - and we stand together. We remain in close contact with U.S. Figure Skating and offer our full support during this incredibly difficult time."
Officials have not said how many people died in Wednesday night s midair crash between the airliner and helicopter but suggested that there might be no survivors.
In 1961, the 18-member U.S. figure skating team died in a plane crash en route to the world championships in Prague.
