After the
September 11 attacks, Princess Haifa was investigated for a sequence of payments allegedly made to a Saudi national by the name of
Omar al-Bayoumi. Investigation has confirmed that some of the payments were in fact forwarded to al-Bayoumi's wife, Manal Bajadr; the significance of these payments (and the extent to which they may have assisted the hijackers) is unclear. In April 1998, Osama Basnan, a Saudi national living in California, wrote to Haifa requesting money for his wife's needed
thyroid surgery. Haifa sent Basnan $15,000, although his wife, Majeda Dweikat, was not actually treated for another two years. The
9/11 Commission Report states in footnote 122: "We have found no evidence that Saudi Princess Haifa al Faisal provided any funds to the conspiracy, either directly or indirectly." At some later point (accounts vary as to when; dates between November 1999 and March 2000 were given, and a Saudi government official put the onset at 4 December 1999), Haifa began sending monthly
cashier's checks to Dweikat of either $2,000 or $3,500, transporting them through
Riggs Bank. In 2002, in regard to the accusations against Prince Turki, her brother, stated "Any allegations about money from my sister reaching the hijackers is allegation and half-truths and totally untrue."{{cite news|title=Ex-Saudi intelligence chief defends princess|work=CNN|date=26 November 2002 ==Ancestry==