The court gave the directive on a habeas corpus petition seeking medical treatment to J Vivek, state Secretary of the banned Communist Party of India (Maoist), arrested last month.
Vivek has been remanded to judicial custody and lodged in the prison at Cuddalore, about 180 km from here.
"We are of the considered view that it is desirable to give effective treatment to Vivek as all required facilities would be available only at the general hospital in Cuddalore. We are constrained to direct the Prison Superintendent to shift him to the hospital for effective and continuous treatment," a division bench headed by Justice K N Basha said.
Directing that the prisoner be admitted to the hospital tomorrow, the court asked police to ensure adequate security and keep the inmate under continuous surveillance.
The High Court posted the petition for hearing on July 5.
Earlier, the prison's medical officer appeared before the bench and submitted that Vivek was provided medication on June 19 since he was taking only water and refused to eat food.
The jailor also appeared before the bench.
Petitioner S Gopal, a friend of Vivek, also sought a direction to the authorities to produce the Maoist leader in court and set him free.
Alleging that he was denied basic facilities and placed under solitary confinement, Vivek has been on hunger strike from June 6, the petition said.
