The NHL Players Association isn't happy about the suspensions of the contracts of six players.
The IIHF announced that the transfers of Alex Radulov and five others are officially under investigation.
All six players are looking to transfer between the NHL and Russia's new Continental Hockey League (KHL). There's currently no formal transfer agreement in place between the two leagues, but both sides are committed to honoring each other's contracts.
The NHLPA said the IIHF has no right to suspend the six players.
NHLPA executive director Paul Kelly said on Saturday of the suspensions:
"Yesterday's announcement by the IIHF that they have suspended certain players from international competition has no basis in fact or law, and constitutes a violation of the rights of these players, the affected players are being unfairly singled out in a dispute between the NHL and the KHL over whether to respect each others' contracts.
"The NHLPA's strong objection to this unilateral action by the IIHF has been registered, and unless this action is reversed, the NHLPA will consider all legal option available."
The six players having their deals reviewed are Radulov, Nikita Filatov, Vikton Tikhonov, Jason Krog, Tomas Mojzis and Fedor Fedorov. All parties have until July 31 to submit documentation to the IIHF.