Georgia's former president Mikheil Saakashvili has been "poisoned" by metals in prison, his legal team has claimed.
The country's main opposition party says Saakashvili should be released because his "condition may lead to coma and death".
The United National Movement (UNM) also called for the former president to receive treatment at a high-level clinic abroad, in the United States or the European Union.
Saakashvili -- the former UNM leader who served as president from 2004 to 2013 -- is currently serving a six-year prison sentence.
He fled the country for Ukraine after the end of his second term in office and was later convicted in absentia of abuse of power.
The 54-year-old was arrested in October 2021 after returning to Georgia before the nationwide municipal elections. He has denounced the charges as political.
Last week, the UNM said Saakashvili was generally healthy at the time of his arrest but had since suffered weight loss and muscle plains.
The party said a toxicological examination showed his body contained high levels of barium, bismuth, and mercury. It also said he most likely suffered a spinal injury in prison and developed a severe form of traumatic stress disorder.
Saakashvili twice went on hunger strike to protest against his imprisonment
Georgian authorities have assured that Mikheil Saakashvili is receiving all necessary care.
Irakli Kobakhidze, chairman of the ruling Georgian Dream party, said there are no grounds for releasing Saakashvili.