Get breaking news alerts and special reports. The news and stories that matter, delivered weekday mornings.

In 2010, a German journalist was watching junior figure skaters compete in Courchevel, France, when he noticed something odd. The journalist, who was sitting behind the judging stand with a group of French chaperones, saw a judge from Italy, Walter Toigo, looking at the scores of his fellow judges.

Peeking at scores is a serious violation of the rulebook of the sport's governing body, the International Skating Union (ISU), because judges are supposed to make their decisions without conferring or colluding. According to the ISU investigation that followed, the chaperones and the journalist noticed Toigo "constantly looking to the left and right at the computer screens of his neighboring judges while he was judging the events. They found his behavior so peculiar that they decided to videotape him."

The videotapes helped persuade the ISU to sanction Toigo. He was banned from judging for two years.

And now he's in PyeongChang, South Korea, ready to judge again. Toigo is one of the judges on an apparent list of 48 chosen to score skaters at the 2018 Winter Olympics.

In the world of international figure skating, no judge has ever received a lifetime ban for breaking the rules. An NBC News investigation found that judges who've been sanctioned for significant violations are back in the game and scoring international competitions. At least four previously sanctioned judges have officiated at international skating events as recently as 2017. One of the judges at the 2014 Olympics who was on the panel that awarded a controversial gold medal to a Russian skater had been sanctioned years earlier for trying to fix an Olympic ice dancing event.

There are 164 judges eligible to score the skating events at this year's Winter Olympics, meaning the 48 on the list plus all the other qualified judges whose countries have been asked to send officials and who may serve as substitutes. In addition to Toigo, this larger pool includes Sviatoslav Babenko, a Russian judge who has been sanctioned twice, once for signaling his preferred order of finish to another judge by tapping with his feet, the other time for talking to another judge in Russian.

Walter Toigo, left, with Carolina Kostner of Italy after her performance at the ISU European Championships in Moscow on Jan. 20, 2018. Grigory Dukor / Reuters file

Babenko returned to judging after both incidents.

Back in 1999, Babenko was accused of exchanging information with a Ukrainian judge during the World Figure Skating Championships in Helsinki. A Canadian television crew had caught Babenko on video tapping out his preferred order of finish to the Ukrainian during the pairs final, and the two had virtually identical scores.

Babenko received a three-year ban that was later reduced to 18 months.

In 2016, he was one of the judges at an international competition in Slovakia.

Let our news meet your inbox. The news and stories that matters, delivered weekday mornings. This site is protected by recaptcha

Heading into the free skate, British pairs Christopher Boyadji and Zoe Jones were in fourth place and hoped to earn a medal.

While they were skating, Babenko and another judge began talking "quite loudly" in Russian, according to an ISU disciplinary report. Their voices were so loud that four other judges "looked at that direction, nearly in unison" during the performance.

Figure-skating judge Sviatoslav Babenko (far left) in 2011. Dmitry Ikunin / FSkate.ru

This was more than bad etiquette, as judges are never supposed to talk during performances, according to ISU guidelines. If they do speak between routines, they are supposed to communicate only in English, the official language of skating, so there is transparency and everyone can understand the conversation.

The disciplinary report did not specify what the judges said in Russian. Russian pairs swept the medals at the event. An American pair finished in distant fourth. Boyadji and Jones, who had fumbled a lift, plummeted to sixth.

The ISU suspended Babenko for the second time. He and Alexandre Gorojdanov of Belarus, the referee, got a six-month suspension.

The judge who was talking and laughing with Babenko, Laimute Krauziene of Lithuania, was reprimanded but not suspended.

Ukrainian figure-skating judge Yuriy Balkov UFSF

All three have judged international events since being disciplined.

Babenko is in the pool of eligible judges for PyeongChang, though he is not on the apparent official list. Gorojdanov and Krauziene are not in the pool, but only because the ISU is not using judges from Belarus and Lithuania at this year's Olympics.

Another judge who was previously sanctioned, Ukrainian Yuriy Balkov, served on the panel that awarded a gold medal to Russian skater Adelina Sotnikova at the Sochi Olympics, in a controversial upset over South Korean favorite Yuna Kim.

Balkov was allowed to judge even though he'd been recorded trying to fix the pairs ice dancing competition at the 1998 Winter Games in Nagano.

Of the 164 judges who are eligible to judge figure-skating events at the 2018 Winter Olympics, 33 now hold or have held leadership positions in their national skating federations. Some of the judges serve or have served in leadership roles in the national federations of Germany, Japan, Russia, Austria, Australia, Canada and the U.S. NBC News

Balkov had met privately with Canadian judge Jean Senft ahead of the Nagano competition, and told her how to rank the outcome, according to Senft.

Senft had grown concerned about Balkov from previous competitions. She told NBC News that she had warned the ISU about his efforts, but was told that she lacked evidence. While at the Nagano Games, she hid a tape recorder in her purse and taped Balkov's proposition.

Balkov was unsuccessful in fixing the ice dancing event.

The ISU initially cited Senft for national bias because she gave the Canadian ice-dancing pair higher marks than the other judges did. When she revealed to the organization that she had a recording of Balkov, he was sanctioned as well.

NBC News was unable to confirm Senft's account with available ISU disciplinary records, but media reports from the time confirm that she was sanctioned for national bias.

Balkov was banned for a year, and then returned to judging, including officiating at the 2002 Salt Lake City Games. At the 2014 Winter Games in Sochi, he was rotated in to judge the women's singles finals, which Sotnikova won. Because of ISU rules in place at the time, the scores given by individual judges were anonymous.

Shortly after Sochi, Balkov was downgraded by the ISU and is not eligible to judge at the Winter Olympics in PyeongChang. But he is still allowed to judge lesser international events.

The skating federations of Italy, Lithuania, Ukraine and Belarus did not respond to requests for comment. The Russian skating federation declined to comment. Babenko could not be reached for comment.

Asked for comment about Walter Toigo and three other previously sanctioned judges who had judged international competitions as recently as 2017, the ISU said on Jan. 30, "We are looking through our archives and will get back to you." Asked to comment specifically on Toigo, the ISU referred NBC News to the decision of the ISU Disciplinary Commission.

The ISU did not immediately respond to a request for comment on why it permits sanctioned judges to resume officiating at international events. It confirmed that no skating judge has ever received a lifetime ban.