Victor An of Russia won two gold medals from the men's 500m and 5,000m relay short track speed skating events, taking his tally to a record six golds on Friday when two doping cases shocked the Winter Olympic Games.

An, a former South Korean who changed his allegiance after he failed to qualify for the 2010 Olympics in Vancouver, won three golds and one bronze in all four men's short track events in Sochi, equal to his feat in 2006 when he competed for his native nation.

He has now won a record six golds in the sport and matched the mark of American Apolo Anton Ohno with eight medals in total.

"This has been the best experience of my sporting career and I will never forget Sochi," An said. "Before the competitions started, I just wanted to concentrate on doing my best and show what I could be on the Olympic stage."

He added, "I'm happy to have tied the record for medals in short track - and I'm even happier to have done it as a Russian."

German biathlete Evi Sachenbacher-Stehle and Italian bobsled athlete William Frullani both tested positive for performance-enhancing drugs during the Games and were sent back home.

Sachenbacher-Stehle, a five-time Olympic medalist, was caught for methylhexanamine after the mass start race on Tuesday, while Frullai has tested positive for the banned stimulant dimethylpentylamine.

Both athletes have been expelled from the Olympic Village by their national Olympic committees and are waiting for further punishments.

"We were shocked by the news and the mood in our team was very bad," said German chef de mission Michael Vesper in a press conference.

"We are in favor of clean sport and against any kind of manipulations. That is why quickly and decisively, in conjunction with the athlete's decision, we have excluded her from the Olympic team. and she is currently on her way back to Germany."

An's victories were Chinese men's nightmare. While their women teammates have claimed two short track golds in Sochi, they will have to wait for another four years for their first winter Olympic title.

Wu Dajing finished second behind An in the men's 500m, and the Chinese team, comprised of Wu, Chen Dequan, Han Tianyu and Shi Jingnan, claimed the bronze in the 5,000m relay, behind An's Russia and the United States after Wu was brought down on the first lap.

South Korea also won their second short track gold through Park Seung-Hi in the women's 1,000m event. China's Fan Kexin won the silver and another South Korean Shim Suk-Hee had the bronze.

Canada became the first country to sweep both men's and women's curling gold at the same Winter Olympics after their men's team crushed Britain 9-3 in the day's final. World champions Sweden beat China 6-4 to win the bronze.

Marielle Thomspon and Kelsey Serwa gave Canada a 1-2 finish in the women's ski cross, with Sweden's Anna Holmlund finishing third.

The North American country has much more to celebrate as they edged arch rivals the United States in the men's ice hockey semifinals. They will fight for the gold against Sweden, the 2-1 winners over Finland.

The Ukrainian team of sisters Valya and Vita Semerenko, Julia Dzhima and Olena Pidgrushna won the biathlon relay gold. It was their country's first gold since 1994.

American Mikaela Shiffrin became the youngest slalom champion in the Olympic history. The 18-year-old settled her on-going battle with 32-year-old Marlies Schild of Austria in superb style, pushing the long-time slalom queen into silver medal position.

Schild has become the first woman to win medals in three successive Olympic slalom races as her compatriot Kathrin Zettel took the bronze.