Iranian authorities executed a 37-year-old man for allegedly "insulting" the prophet Jonah and accused him of committing adultery, the Guardian reported on Monday.

The Guardian quoted an anonymous source's statement to a U.S. civic advocacy group, the International Campaign for Human Rights in Iran, saying Mohsen Amir-Aslani was originally arrested on orders of intelligence officials nine years ago.

"He was initially held for making innovations in Islam and providing his own interpretations of the Qur'an but later he was accused of insulting prophet Jonah and also faced accusations of having sex outside marriage," the source was quoted as saying. "They alleged that he had sexual relationships with a group of the people who participated in his classes."

According to Amir-Aslani's wife, Leila, Officials reportedly listed "spreading corruption on earth" and "innovations in the religion" as the reasons for Amir-Aslani's conviction before adding the accusations of "illicit sexual relationships." He was executed by hanging last week.

Amir-Aslani also reportedly interpreted the story of the prophet Jonah as being "symbolic." Jonah appears in Chapter 10 of the Qur'an in a story similar to his appearance in the Hebrew Bible. The Qur'an's version of the story states that Jonah was swallowed by a fish and imprisoned before he "glorified Allah" and repented for his actions.