The man, identified by Russian media as Andrei Fomochkin, director of the Republican Centre of Olympic training for Athletics in Belarus, was hailed as a hero by both Russian and Belarusian officials.
But his action fell foul of the IPC's ban on political gestures.
"The IPC will be speaking to NPC Belarus this morning to remind them that political protests are forbidden at the Paralympic Games," the IPC said in a statement, adding that the individual had been identified and his accreditation cancelled. The statement did not name the person.
In Russia, where the ban for state-sponsored sports doping has been fiercely contested, there was high praise for Fomochkin.
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"A hero has appeared today amongst us," Russian Foreign Ministry spokeswoman Maria Zakharova told Interfax news agency.
"(He) showed solidarity with people who were disgracefully treated in an inhumane way in not being allowed to compete at the Paralympics," Zakharova added.
Russia's Paralympic Committee head Vladimir Lukin enthused:
"During this difficult period, he remembered us... It's great that the Belarusians thought about the closest country to them, about Russia. We won't forget this."
In Belarus, the Foreign Ministry also commended Fomochkin.
"This was the right thing. Our sportsman acted in a serious, manly and friendly way," the Ministry's press secretary Dmitri Mironchik told RIA Novosti. "If we need to answer for these gestures, then we will answer," he added.
(Reporting By Dmitriy Rogovitskiy in Moscow and Andrew Downie in Sao Paulo,; Editing by Clare Lovell and Frances Kerry)
