Mr Trad once proposed to another woman with the consent of his wife, Hanefa, but the second marriage did not proceed. "I certainly would not have entertained the thought of having a relationship without a religious marriage, and I thought the relationship with that person was developing to the stage where we had become too friendly," he told the program.

"This idea of plural sexual relationships, it is not so much frowned upon by society as long as these people don't say we want a polygamous relationship."

Mr Trad's mother was a third wife in a polygamous relationship overseas. He said women were choosing to enter such relationships and had admiration and respect for one another.

"In a sense, it's a compliment to the original partner that if he didn't find marriage to be so good, why would he go into it again," he said. "In a sense, he's saying that his first wife has made life like heaven for him, so he's willing to provide the same service, love and support to a second woman."

Mrs Trad said many people in polygamous marriages kept it a secret, not only because it was illegal, but because society did not accept it. Asked if it was just about wanting sex with more women, she said: "It can be, but having it in the right way instead of having it (with) a prostitute or just date." AAP