GANGNEUNG, South Korea — Victoria Moiseeva, in a high-stakes match, found it impossible to push a brewing scandal out of her mind on Monday morning at Gangneung Curling Centre. It was the first time in her life, she said, that she could not fully focus while competing.

“It’s a catastrophe,” she said.

Moiseeva, the skip, or head curler, of the Russian women’s team was referring to the possible effects of a failed doping test by a fellow Russian curler here at the 2018 Winter Olympics.

She and some other Russian athletes fretted that the damage from this single case could be widespread.

“This is simply terrifying to think about,” she said.

The athlete, Alexander Krushelnytsky, is the first from Russia to come under investigation at these Games for using a banned substance, jeopardizing the bronze medal he won last week in the mixed doubles competition with his wife. It also complicates Russia’s effort to rehabilitate its image after a vast state-backed cheating scheme at the 2014 Sochi Games it hosted left it nominally barred as a team from the Games.

The International Olympic Committee had been considering allowing Russia to march under its own flag at the closing ceremony Sunday. But several members now privately suggested that allowing that would risk appearing to appease Russia and could undercut an effort to play up the peacemaking presence of a North Korea delegation at the Games.

On rare occasions, there have been doping violations in curling, since it is, on balance, a taxing feat of endurance to sweep the broom round after round. The sport, however, is not accustomed to being at the center of such a high-profile case, so the news sowed confusion and puzzlement among the curlers here.

Curling is a sport in which players slide stones on a sheet of ice towards a target area which is segmented into four concentric circles. It is related to bowls, boules and shuffleboard. Two teams, each with four players, take turns sliding heavy, polished granite stones, also called rocks, across the ice curling sheet towards the house, a circular target marked on the ice. Each team has eight stones, with each player throwing two. The purpose is to accumulate the highest score for a game; points are scored for the stones resting closest to the center of the house at the conclusion of each end, which is completed when both teams have thrown all of their stones. A game usually consists of eight or ten ends.

Curling sheet of ice

Not to be confused with another Scottish sport called Hurling.