The family of a British grandfather languishing in an Iranian prison say he could be freed within a week.

Kamal Foroughi, 76, has spent the last five years in Iran’s notorious Evin prison after Iranian authorities convicted him of espionage in 2013 and sentenced him to seven years in prison.

He was also handed an additional year for possession of alcohol.

“We have just had some great news,” his son Kamran said in a statement posted to petition site change.org Tuesday.

“76 year old Grandpa Kamal’s lawyer visited him last Saturday and told him some news from the Judiciary and Prosecutors’ Office that all the relevant parties have agreed and signed for his release,” he wrote, adding “Fingers crossed our nightmare will be over within a week.”

Foroughi, an engineer by training, was working as a consultant in the capital city of Tehran for the Malaysian national oil and gas company Petronas when Iranian authorities took him into custody in May 2011, taking him from his apartment without any warrant for his arrest, according to his family.

“My dad is probably the oldest and loneliest prisoner in Iran,” his son, Kamran Foroughi, said in an interview with The Foreign Desk, last year.

“We want Dad to come home to his family in the U.K. and are increasingly worried that he is not receiving medical treatment,” Kamran said.

According to his son, Foroughi was told he would be released at the four-year anniversary of his imprisonment last May.

For over a year, he has been waiting for a full medical checkup but has not received any indication that he would be seen by a doctor, he said.

Foroughi’s family had originally stayed quiet, fearing that going public might be detrimental to his case, but as his age and concern for his health become a priority, they broke their silence and initiated a public campaign to have him released on “compassionate grounds.”

Foroughi’s wife, two children and two granddaughters live in London, where Foroughi emigrated to from Iran over 30 years ago.

“We are still not clear about what the charges are for, or why my father has been imprisoned, but at this point we are not focusing on those details, we just want him to come home,” Kamran said.

“I have a simple message (to the Iranian government) from my daughters: please let Grandpa Kamal come home,” he said.

Amnesty International also took up his case in a report documenting the known details of his arrest and imprisonment, calling for urgent action by the international community to pressure the Iranian government for his release.

The report stated that he “suffers from different medical conditions,” and that “prior to his arrest, his doctors had said that he needed specialized medical tests and check-ups, including screening for cancer.”

According to Foroughi’s son, his father has been transferred from prison to a nearby hospital several times since December 2014, but that he still has had no access to the specialists he needs.

The family said they attempted to reach Iranian judicial authorities both independently and through his lawyer and have not received any direct answers about the details of his arrest or specifics about the spying charges.

Last week, Britain’s Foreign Office issued a travel warning to U.K. citizens, particularly those of dual Iranian nationality, advising them of the risks of travelling to Iran.

Despite the loosening of travel restrictions to Britons following the July 2015 nuclear agreement between Iran and world powers, the U.K. revised its travel advisory Friday amid concerns over the continued imprisonment of Foroughi and the recent detention of Nazanin Zaghari-Ratcliffe, a British-Iranian mother arrested by Iranian authorities as she was about to board a flight back to the U.K. following a family visit.