Iranian authorities have imposed criminal charges on a jailed couple for hosting parties in Tehran, according to officials and a human rights group.

Prosecutor Abbas Jafari Dolatabadi said a husband and wife were charged because they "provided alcoholic drinks, and encouraged corruption and debauchery by holding mixed [gender] parties."

He did not name the couple, but the U.S.-based Center for Human Rights in Iran (CHRI) said he was referring to Iranian-American dual citizen Karan Vafadari and his wife, Afarin Nayssari.

The couple owned an art gallery in Tehran and sometimes hosted events for dignitaries and diplomats before their arrests in 2016.

Dolatabadi said that 4,000 liters of alcohol were found in the basement of the couple’s building in northern Tehran.

The couple are members of the minority Zoroastrian faith, who are allowed to have alcohol for private use but are forbidden from sharing it with Muslims, who make up the majority of the population.

CHRI has called for their immediate and unconditional release.

In a statement on March 10, the rights group said the couple's "imprisonment on completely unsubstantiated charges and without any evidence of wrongdoing represents a brazen defiance of the law."

With reporting by AFP