American families who lost members in September 11 attack on twin towers have launched a campaign in Florida to condemn Saudi efforts for laundering its dark history by financing a public gulf event in July.

The families' 9/11 Justice advocacy group aired an advertisement in Florida on Tuesday, denouncing LIV Golf, a professional golf tour that is financed by the Public Investment Fund, the sovereign wealth fund of Saudi Arabia.

Former US president Donald Trump’s golf club in Bedminster, New Jersey, hosted a LIV Golf tournament in July.

The 9/11 Justice broadcast the ad in the run-up to LIV Golf's plans to hold another tournament at Trump National Doral Golf Club in Miami, which is set to begin on Friday.

The 9/11 families dismiss the golf tour as Riyadh's bid at "sportswashing" its role in the attacks as well as numerous other atrocities that the kingdom has unleashed on both its own citizens and people living elsewhere across the world.

The advertisement also made mention of Jamal Khashoggi, a dual US-Saudi citizen and Riyadh critic, who was killed and dismembered at the Saudi Consulate in Istanbul in 2018.

"The Saudis are using oil profits to fund exhibition golf, hoping to distract you from their policies of oppressing women, murdering journalists, and supporting the 9/11 terrorists,” the ad said.

"This is the second LIV tournament hosted by Donald Trump at his golf courses this year, and that is painful and really disappointing," 9/11 Justice's President Brett Eagleson, whose father, Bruce Eagleson, died in the terrorist attacks, said in a statement. "We continue to urge Mr. Trump to meet with us to hear our views."

"The evidence of Saudi government officials' participation in this attack on America could not be clearer."

Fifteen of the 19 hijackers that staged the 9/11 attacks were from Saudi Arabia. The kingdom has, however, long denied any role in the attacks, which killed nearly 3,000 people.

Also in July, Saudi Arabia enlisted the Chicago-based Edelman PR company, one of the biggest US public relations firms, in an attempt to improve its image throughout the United States.