BEIRUT (Reuters) - The son of an 81-year-old Iranian-American jailed in Iran urged the authorities on Monday to allow his father to serve his sentence at home after he was admitted to hospital for a second time in a week.

FILE PHOTO - Iranian-American Baquer Namazi is shown in this undated family handout picture released February 27, 2016. Courtesy Namazi family/Handout via REUTERS

On Sunday night, Baquer Namazi’s heart rate doubled from 60 to 120 beats per minute and he was suffering from a severe depletion of energy and fluctuations in blood pressure, his lawyer Jared Genser said in a statement.

Last Wednesday, Namazi, a former Iranian provincial governor and ex-UNICEF official, was taken to the Evin prison infirmary after a severe drop in blood pressure.

He is serving 10 years on charges he spied and cooperated with the United States, but his health has deteriorated over the nearly two years he has been in prison. He has denied the charges against him.

In January, he was taken to the hospital for a sharp drop in blood pressure and irregular heartbeat, and in September he underwent emergency surgery to install a pacemaker, his family has said.

The Iranian government’s medical examiner recommended on Feb. 4 he be granted a three-month leave from prison on medical grounds, the lawyer said last week.

But instead of being granted the leave, Namazi was told on Feb. 6 to report back to the prison in Tehran, he said.

“I don’t know what needs to happen for the Iranian authorities to allow my father to stay out of prison and heed the advice of their own medical examiner panel,” Namazi’s son Babak said in the statement released by the lawyer.

“I beg the authorities to let him stay at home on parole on humanitarian grounds. It is obvious that if they do not, he could die at any time.”

The Iranian judiciary could not be immediately reached for comment about Namazi.

Another son, Siamak, an Iranian-American businessman in his mid-40s, was arrested by Iranian security forces in October 2015. Iranian authorities detained Baquer Namazi a few months later when he tried to visit his son. He is also in Evin and has denied the charges.