FILE PHOTO: A supporter of Turkey's main pro-Kurdish Peoples' Democratic Party (HDP) holds a portrait of their jailed former leader and presidential candidate Selahattin Demirtas during a campaign event in Istanbul, Turkey, June 17, 2018. REUTERS/Huseyin Aldemir/File Photo

ISTANBUL (Reuters) - The jailed former head of Turkey’s main pro-Kurdish party was taken to hospital on Monday, his party said, after he lost consciousness last week following chest pains.

One of Turkey’s best known politicians, Selahattin Demirtas has been in jail for more than three years on several charges including terrorism. He could be sentenced to 142 years in jail if found guilty in the main case.

Aygul Demirtas, his sister and one of his lawyers, said earlier that Demirtas had not been taken to the hospital despite losing consciousness on Nov. 26 after experiencing chest pains and trouble breathing.

His Peoples’ Democratic Party (HDP), the second largest opposition party in Turkey’s parliament, said shortly after that Demirtas was taken to hospital after two of its lawmakers visited Demirtas in prison.

The chief prosecutor in the western province of Edirne, where Demirtas is being held, said initial tests last week had indicated no health issues. It said appointments were made at a hospital to conduct detailed tests, and Demirtas had been transferred to the hospital on Monday.

Demirtas, 46, had remained unconscious for a long time after fainting on the morning of Nov. 26, lawyer Demirtas said on Twitter.

An electrocardiogram was carried out on Demirtas but the prison doctor asked that he be taken to hospital for examination by cardiology, neurology and gastroenterology experts, she said.

In September, prosecutors in Ankara launched a new investigation into Demirtas and requested his detention after a court lifted his arrest warrant in the main case. Demirtas denies the charges against him.

Ankara accuses the HDP of links to the outlawed Kurdistan Workers Party (PKK), which has waged a decades-long armed struggle against the Turkish state. The HDP denies links to terrorism.