TEHRAN, Iran - Two French researchers held for months in a Tehran prison on charges of violating Iran's state security laws have petitioned prison authorities to allow them to get married, their lawyer said Friday.

The two - Fariba Adelkhah Adelkhah and Roland Marchal, both in their 60s - filed separate requests to Evin prison authorities, their lawyer, Saeid Dehghan, said. He also expressed concern for Adelkhah's deteriorating health amid a hunger strike she has been on since December.

Iranian officials disclosed last July that Adelkhah, a dual French-Iranian national who is a prominent anthropologist who often travelled to Iran for research on post-revolutionary Iranian society, had been arrested on espionage charges. Those charges were later dropped but security-related charges remain against her.

In December, Adelkhah went on a hunger strike to protest her's and Marchal's detention.

“She remains on hunger strike, her legs are weak and she walks with difficulties,” the lawyer said. He said, without elaborating, that “her kidneys have faced some problems.”

Adelkhah's fellow researcher, Marchal, was arrested as he tried to visit her, France revealed in October. He is being held in a men's ward in Evin on charges of spreading propaganda.

In December, France summoned the Iranian ambassador to Paris to say it considered the months-long detention of Adelkhah and Marchal “unacceptable” and sought permission for consular officials to visit them.

Dehghan, the defence attorney, told The Associated Press that the French Embassy has had consular access only to Marchal. Iran doesn't recognize dual nationality for its citizens.

He said a decision on whether his clients will be allowed to marry is expected next week. They have been partners for 38 years in France, he said.

“If permitted to marry, they will be able to meet and see each other inside the prison,” he said, explaining that Iranian laws prohibit extra-marital relations.

Iran is holding several foreign and dual nationals, including five U.S.-Iranian nationals. Among them are Siamak Namazi and his 83-year-old father Baquer Namazi. The dual U.S.-Iranian nationals face 10-year sentences each after they were convicted of collaborating with a hostile power.

On Friday, Iranian media published a letter from Namazi to judiciary chief Ayatollah Ebrahim Raisi, in which he said authorities didn't grant him a short leave after he provided the required bail.

In the letter published on the pro-reform Ghanoon newspaper's Telegram channel, Namanazi said he needs several weeks leave to tend to his ill father, whose health condition he described as “dangerous.” He did not elaborate.

Iran says Baquer Namazi is now on a prison furlough However, the Namazis say he remains unable to leave Iran.

A prisoner exchange in December saw Iran free a Chinese-American scholar from Princeton who had been held for three years on widely criticized espionage charges. It was seen as a rare diplomatic breakthrough between Iran and the U.S. However, it came prior to the U.S. killing of Iran's top general in Iraq in January, which has dramatically escalated tensions between Washington and Tehran.

Two Australians were freed in October while Australia freed an Iranian in what appeared to be a prisoner swap.

This story has been corrected to show that of the French couple, only the woman holds dual Iranian-French nationality.