The 56-year-old Saudi, detained in the south-western province of Jazan near the border with Yemen, is being questioned over charges that he is married to three Saudi and three Yemeni women, Al-Watan newspaper reported.
The man is an employee with the Commission for the Promotion of Virtue and Prevention of Vice, or religious police commonly known as the Muttawa, which is in charge of enforcing a strict Islamic moral code in ultra-conservative Saudi Arabia.
He has denied the charge, claiming he has divorced two of his spouses, the newspaper said.
The province's governor has ordered the formation of a committee to look into the case, Al-Watan said.
Muslim men can keep up to four wives at a time under sharia, or Islamic law, which is applied in oil-rich Saudi Arabia.
Source: The Age