Jessica Ennis-Hill's coach Toni Minichiello has expressed his belief that Tatyana Chernova's drugs ban needs to be "looked at" after she kept her world title.
Last week, the 27-year-old Russian athlete was handed a two-year ban, which has been backdated to June 22, 2013.
Chernova, who beat Ennis-Hill to gold at the 2011 World Championships in Korea, has had results from August 15, 2009 to August 14, 2011 annulled.
The suspension will expire on June 21, which means that Chernova could compete in qualification for the 2015 World Championships, as well as the Rio Olympics next year.
"It would be frustrating if she lines up on the starting line but those are the rules out there and we need to abide by them," Minichiello told BBC Sport.
"That is why we think WADA needs to look at its code and penalties to show there is potentially a loophole that needs to be looked. I'm sure the Russian anti-doping agency have administered suspensions according to the rules, so therefore it needs to be looked at."
Chernova was punished after a drugs sample from 2009 was re-tested.
