MOSCOW: Former Russian Prime Minister Yegor Gaidar has been hospitalised with an undiagnosed illness, his daughter Maria said on Wednesday.

Gaidar, 50, suddenly fell ill while on a visit to Ireland last week.

"At a conference in Dublin November 24, my father suffered sudden problems with health. He lost consciousness and stayed unconscious for three hours, at an intensive care unit in a Dublin hospital," Maria said.

According to her, there was a serious threat to his life as doctors still cannot diagnose the cause of his illness.

The father of Russia's post-communist liberal economic reforms is known in his country as a man who gave "shock without therapy" while dismantling the Soviet economic system.

Gaidar is currently the director of the Institute of Transitional Economy serving as a think-tank for the Kremlin's economic policies.