Geoffrey Nice, who led the prosecution in the case of former Serbian President Slobodan Milosevic, who was tried for war crimes in Croatia, Bosnia and Kosovo in the 1990s, shared the information with the BBC.
"He (Putin - ed.) will remain an alleged criminal until and unless he submits himself for trial, or is handed over for trial and acquitted," he said.
At the same time, Nice believes that Putin's trial is unlikely because the ICC does not have the authority to arrest suspects without the cooperation of the government. Russia is not a member of the ICC, which means that the court, located in the Hague, has no authority there.
"That (Putin's trial - ed.) seems extremely unlikely, so he will remain an alleged criminal until the end of his life," said Nice.
At the same time, he noted that the arrest warrant could affect Putin's ability to travel abroad. Now he can be arrested in any of the court's 123 member states.
On March 17, the International Court of Justice in The Hague issued an arrest warrant for Putin. He is suspected of forcibly deporting Ukrainian children.
China said that the International Criminal Court, which issued the arrest warrant for Putin, should take an "objective position."