One of Osama Bin Laden's wife and six children, missing since the 2001 invasion of Afghanistan, are under house arrest in Iran, a Saudi-owned newspaper reported Wednesday, citing Omar Bin Laden, the fourth son of the al-Qaeda leader.

Omar bin Laden, who lives in Qatar, said he only learnt his family members were still alive after receiving a call last month from his brother Uthman, who had been lent a mobile phone by a young Iranian.

Until a month ago we did not know where the siblings were, Omar bin Laden, 29, told the Asharq Al-Awsat newspaper.

Iran's foreign ministry spokesman Ramin Mehmanparast did not deny that six members of the bin Laden family were in Tehran, at a weekly press conference on Tuesday.

Omar also said five of his father's other children are currently in Saudi Arabia, while three, along with his mother Najwa, are in Syria.

He hopes the family in Iran will be granted permission to leave.

We just want to be together as a family. I have now got 11 nieces and nephews, born either in Afghanistan or Iran that I have never seen. Some people may find this story unnerving, but the child can't be judged by the sins of their father, the Times quoted him as saying.

The family was living in Afghanistan when the U.S. military began air strikes on the country following the Sept. 11, 2001, attacks. They crossed the border into neighboring Iran and then were held there, according to the newspaper.

 Osama bin Laden, now in his 50s and rumored to be in poor health, is the world's most-wanted man with 25 million dollars on his head. He is thought to be hiding out in mountains on the Afghanistan-Pakistan border.