The European Criminal Bar Association (ECBA) has issued an urgent request for international intervention on behalf of Iranian human rights activist Reza Khandan, the husband of prominent human rights lawyer Nasrin Sotoudeh.

Khandan was arrested on Friday after Iranian security forces raided his home. His daughter, Mehraveh Khandan, revealed in an Instagram post that her father was detained at his residence. The reason for his arrest has not been disclosed.

In its statement, the ECBA said Wednesday, “We call for an end to the judicial harassment of Reza Khandan and Nasrin Sotoudeh, in line with the UN Declaration on Human Rights Defenders and the UN Basic Principles on the Role of Lawyers.”

Khandan has been arrested in the past for his activism and his support of his wife’s campaign against Iran’s mandatory hijab laws.