The IBSF clarified that the reason for the disqualification was that during a hearing in early January, its Anti-Doping Hearing Panel (ADHP) concluded that the athletes "have committed an Anti-Doping Rule Violation (ADRV) for the use of a Prohibited Substance and the Use of a Prohibited Method (i.e. urine substitution)."
"Mr Aleksander Kasjanov, Mr Ilvir Khuzin Mr Aleksei Pushkarev and Mr Aleksander Zubkov will each be sanctioned with a period of ineligibility of two years, starting from the day of their provisional suspension, for the first 3 Athletes mentioned this being December 13, 2018, therefore ending on December 12, 2020, for Mr Zubkov this being December 19, 2018, and therefore ending on December 18,2020, during which period they are not entitled to participate in any competition or activity", the IBSF said in a statement.
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According to the statement, the term "activity" includes "administrative activities, such as serving as an official, director, officer, employee, or volunteer of the national organizations."
The athletes are eligible to appeal the decision with the Court of Arbitration for Sport (CAS).
The IOC Commission previously found Zubkov guilty of violating anti-doping rules, annulled his 2014 Olympic results, and banned him for life from participating in future Games. Later, the CAS replaced the lifetime ban with one that applied only to the 2018 Pyeongchang Games, but Zubkov's Sochi results have remained annulled.
In December, the IBSF provisionally suspended Zubkov for violating anti-doping rules at the Sochi Olympics. This verdict was motivated by the CAS' decisions.
Zubkov was elected as president of the Russian Bobsleigh Federation in June 2016. In July of last year, he was re-elected for a new four-year term.