According to an Ukrinform correspondent, lawmakers were photographed in the parliament holding a banner with the inscription #FreeSentsov.
Members of two influential standing committees of the Canadian parliament - on security and defense, as well as on foreign affairs - joined the flash mob.
The photo ceremony was also attended by Ukrainian MPs, who were on an official visit to Ottawa.
On June 12, Sentsov was also supported during the premiere of the movie "Cyborgs" in Ottawa, which took place in the cinema hall of the Canadian Museum of History.
On May 16, Sentsov declared an indefinite hunger strike demanding the release of all Ukrainian political prisoners in Russia and areas occupied by Russia.
According to the Ukrainian Foreign Ministry, at least 24 Ukrainians are political prisoners in Russia and more than 40 in Russian-occupied Crimea. This list also includes Ukrinform journalist Roman Sushchenko, who was sentenced in Russia to 12 years of imprisonment in a high-security penal colony on trumped-up charges of "espionage."