MOSCOW, Nov 17 (Reuters) - Georgia's hunger-striking former president Mikheil Saakashvili is being mistreated in a prison hospital and urgently needs special treatment in intensive care, a Georgian human rights group said on Wednesday.

Saakashvili, who has been on hunger strike in prison for more than a month and a half, may soon face various health complications, including heart failure, gastrointestinal bleeding and coma, the Public Defender of Georgia, or human rights ombudsman, said in a statement.

"As the patient's condition is critical, it is immediately recommended to continue his treatment in a functional and well-experienced... hospital, in particular in the intensive care unit," the Public Defender said.

Experts have visited the clinic where Saakashvili is being treated kept and concluded that the requirements of the 53-year-old former president, including high-tech examination, cannot be met by the prison, according to the rights group.

The Public Defender group said earlier this week the prison hospital treating Saakashvili lacks proper medical equipment and other inmates there have threatened and abused him. read more

Saakashvili was arrested on Oct. 1 after returning from exile to Georgia to rally the opposition on the eve of local elections, in what he described as a mission to save the country. He faces six years in prison after being convicted in absentia in 2018 of abusing his office during his 2004-2013 presidency, charges he rejects as politically motivated.

Saakashvili is the most prominent and divisive living figure in Georgia's post-Soviet history, having come to power via a peaceful "Rose Revolution" in 2003 and led the country into a disastrous war with Russia five years later.

His case has drawn thousands of his supporters onto the streets in recent weeks and raised political tensions in the country of 3.7 million people. The state security service has accused him of plotting a coup.

Georgian authorities have said Saakashvili will not be pardoned.