LONDON (Reuters) - A Moscow court ruled on Tuesday that Russia's Investigative Committee is not obliged to investigate two attempts on the life of jailed dissident Vladimir Kara-Murza, independent news outlet Mediazona reported.

Moscow-born Kara-Murza, who has both Russian and British passports, was jailed last April for 25 years on treason charges after he repeatedly condemned Russia's war in Ukraine and lobbied for Western sanctions against Moscow. His appeal against the sentence was rejected this month.

The 42-year-old politician and former journalist has survived two poisoning attempts. He became ill and was hospitalised in Moscow in 2015, a few months after his colleague, opposition leader Boris Nemtsov, was gunned down while walking across a bridge near the Kremlin walls.

In 2017, Kara-Murza was placed in a medically induced coma and put on life support after the onset of similar symptoms.

A joint investigation led by the Bellingcat outlet subsequently found that Kara-Murza was trailed by the same unit of Russia's Federal Security Service (FSB) that allegedly poisoned opposition leader Alexei Navalny in 2020. Navalny died in an Arctic prison in February.

Kara-Murza's wife Evgenia says the poison attempts have left him with a nerve disorder and she fears for his life in prison.

His lawyer sent requests to the Investigative Committee to investigate the poisonings, which were denied. The Moscow City Court on Tuesday rejected Kara-Murza's appeal against those decisions, said Mediazona, which reports on human rights and court cases in Russia.

Kara-Murza called investigators' claims that they had looked into the murders and interviewed witnesses "a direct, documented lie" in court, speaking via video link from the Siberian prison where he is incarcerated, Mediazona reported.

He also spoke out in support of Zhenya Berkovich and Svetlana Petriychuk, a Russian theatre director and playwright whose trial began on Monday in Moscow, according to the report.

(Reporting and writing by Lucy Papachristou; Editing by Christina Fincher)