UPDATE 2-Doping-Russian race walker Kirdyapkin stripped of 2012 Olympic gold

* CAS upholds IAAF appeals over RUSADA bans

* Australian in line for walk gold medal (Updates with IAAF reaction)

LONDON, March 24 (Reuters) - Russian Sergey Kirdyapkin is set to be stripped of the 50-km walk gold medal he won at the 2012 London Olympics after the Court of Arbitration for Sport (CAS) upheld an appeal by the IAAF against the Russian anti-doping agency (RUSADA).

Two more Russian athletes are set to lose their London Games medals after the sport’s governing body (IAAF) appealed on six cases where they said RUSADA had been “selective” in annulling previous results of the athletes after they were banned for irregularities in their biological passports.

CAS upheld all six appeals, which included London 2012 3,000 metres steeplechase champion Yuliya Zaripova, former Olympic champions Valery Borchin and Olga Kaniskina, 2011 world champion Sergei Bakulin and world silver medallist Vladimir Kanaykin.

Kaniskina is also set to lose her silver medal from the 20km walk race in London after her results were disqualified from 2009 to October 2012 while Zaripova’s disqualification period also includes her London Games’ gold-winning race.

All six were issued bans ranging from two years to life by Russia’s anti-doping agency (RUSADA).

IAAF, however, appealed to CAS over the punishments in March last year, saying it disagreed with the “selective” disqualification of results that allowed the athletes to keep titles.

The decision was welcomed by the IAAF which said it was starting the reallocation of medals.

“The IAAF will immediately proceed to the effective disqualification of results, re-rankings and reallocation of medals in all competitions under its control,” it said in a statement.

“With respect to the Olympic Games, the IAAF will inform the International Olympic Committee of the CAS decisions and request the disqualification of results and the reallocation of medals.”

Kirdyapkin’s competitive results between Aug. 20, 2009 to Oct. 15, 2012 were annulled, meaning his gold medal at the London Games would also be scrapped.

Australia’s Jared Tallent, silver medallist behind Kirdyapkin, who had long campaigned for the Russian’s Olympic title to be stripped, would receive the gold medal if upgraded by the International Olympic Committee.

“History has been rewritten tonight. I am the Olympic champion and justice has been served. I’m very excited to see the result amended and thank all those who have supported me across this journey,” Tallent said in a statement.

“For me, this outcome allows me to celebrate a moment that every athlete dreams of and I look forward to sharing the experience with my family, including wife Claire, my Mum, Dad and siblings.”

China’s Si Tianfeng is set to move up to second with Ireland’s Robert Heffernan to be upgraded to bronze.

Russian athletics was banned from international competition in November following a report by the World Anti-Doping Agency which exposed systematic state-sponsored doping and related corruption.

The IAAF said earlier this month that Russia still had “significant work” to do for the ban to be lifted ahead of the Rio Olympics in August.

More positive drugs tests have emerged in recent weeks involving Russian wrestlers and swimmers. (Reporting by Mitch Phillips and Karolos Grohmann, Editing by Pritha Sarkar and Raissa Kasolowsky)