A Russian court on April 15 rejected imprisoned environmental activist Yevgeny Vitishko's request for early release.
Vitishko, 41, was jailed after raising concerns about the environmental impact of the 2014 Winter Olympics in Sochi.
A district court in the Tambov region, where he is serving a three-year sentence, agreed with prison authorities who said he did not deserve early release.
Vitishko was handed a three-year suspended sentence in 2012 for spray-painting a fence in a forest near Sochi to protest what he said was illegal construction.
But In December 2013, a ruled that he had violated the terms of the sentence and sent him to prison.
On April 14, Amnesty International urged Russian authorities to immediately release Vitishko, who started a hunger strike on April 7.
Amnesty has named Vitishko a "prisoner of conscience" and the prominent Moscow-based human rights group Memorial considers him a political prisoner.