The IAAF, world athletics' governing body, banned the Russian track and field team last month and on Thursday that decision was rubber-stamped by the Court of Arbitration for Sport (CAS).

The Swiss-based body rejected an appeal against that ban by the Russian Olympic Committee and 68 individual athletes.

It followed a momentous week for world sport which started with the publication of a World Anti-Doping Agency-commissioned report into a state-directed doping conspiracy that went much further than athletics.

Gorbachev, 85, wrote in the letter, posted on the Mikhail Gorbachev Foundation website: "Ladies and gentlemen, I am writing to ask you to take into account my position in ruling on admitting Russian athletes, as well as Paralympians, to participate in the Olympic Games in Rio de Janeiro.

"I support the fight against the use of banned substances in sports. It is an evil that must be eradicated. The athletes whose use of doping has been proven must be banished from competition.

"I am deeply troubled by the fact that Russian citizens are among the officials and athletes who used doping and fraud for 'victory at any price'. Serious conclusions should be drawn from this. It is necessary to conduct a thorough investigation, punish those responsible and take steps to prevent anything similar in the future. I am sure that this will be done.

"However, I am concerned and deeply saddened by the possibility that, in the event Russian athletes are banned from participating in the Olympics, persons not culpable would be punished as well as those who are guilty.

"I regard the principle of collective punishment as unacceptable. I am convinced that it is contrary to the culture of the Olympic movement, based on universal values, humanism and the principles of law.

"I hope that you will give due attention to these arguments and take a just decision."