WASHINGTON -The campaign advertising war turned even more negative yesterday with the airing by a Democratic advocacy group of two spots accusing President Bush of suppressing evidence linking the Saudi royal family with the September 11 terror attacks because of past business ties.

The Michael Moore-style ads broadcast by the Media Fund, a 527 group led by a former Clinton deputy chief of staff, Harold Ickes, say that Mr. Bush and his family are too close to the “wealthy, powerful, corrupt” House of Saud, and that as a result of their friendship the president ordered concealed all evidence of Saudi involvement in the terror attacks on New York and Washington.

The ads also take a swipe at a former secretary of state, James Baker, a top Bush family adviser, for the defense by his law firm, Baker Botts, of Saudi Arabia in lawsuits filed by the families of the victims of the attacks. Neither Mr. Baker nor his law firm responded to requests last night for comment.

According to the Media Fund’s Erik Smith, the spots drive to the heart of the question about whether “U.S. foreign policy under Mr. Bush has been manipulated because of the relationship between the Saudi royal family and the Bush family.”

Mr. Smith said the fund had invested a half-million dollars in the ads and planned to run them initially in Missouri and Washington, D.C. “We will add markets and additional commercials while we are fund-raising,” he said.

Bush campaign officials denounced the ads, saying they represented a new low in the campaign and are a rehash of the “baseless charges” made by Mr. Moore in his documentary “Fahrenheit 9/11.”

“The charges are ridiculous,” a Bush campaign spokesman, Kevin Madden, told The New York Sun.

“The tendency of the liberal 527s and the Kerry campaign to avoid discussing the real issues of foreign policy, health care, education, and the economy is something they do at their peril,” Mr. Madden said.

He accused the Media Fund and the Kerry campaign of coordination, which would violate election laws.

“The Media Fund is run by Harold Ickes, who sits on the Democratic National Committee,” he said.

The first spot, entitled “Missing Pages,” pictures Mr. Bush in several settings with Saudi leaders, including casual conversation with the Saudi ambassador, Prince Bandar, a close family friend who reportedly was given several years ago the nickname “Bandar Bush” by the president’s mother, Barbara.

Mr. Bush is also pictured embracing Crown Prince Abdullah.

An announcer then states: “When congressional investigators issued their report on 9/11, there were 28 pages missing. Twenty-eight pages of evidence that the Saudi government funded the terrorists who killed nearly 3,000 Americans. Evidence kept secret under orders from George Bush.”

The spot continues: “Was it to protect his Saudi friends or was Bush helping Jim Baker, a top adviser, whose law firm is defending the Saudis in a lawsuit against the victims’ families? Either way, Bush and the Saudis are too close for comfort.”

The 28 pages highlighted in the advertisement refer to a section of the 9/11 commission’s report that the White House insisted be blacked out. The section dealt with purported Saudi government links to the hijackers. In his recent book, “Intelligence Matters: The CIA, the FBI, Saudi Arabia and the Failure of America’s War on Terror,” Senator Graham of Florida, who was ranking Democrat on the Senate Intelligence Committee, says the redacted section provides evidence of Saudi government ties to the Al Qaeda plot.

Mr. Graham says much of the redacted evidence centered on a Saudi then living in San Diego, Omar al-Bayoumi, whom the senator calls a Saudi government spy. Mr. al-Bayoumi befriended two of the 9/11 hijackers, Khalid Almihdhar and Nawaf Alhazmi, when they first arrived in the country.

Mr. Graham’s conclusions about Mr. al-Bayoumi conflict, however, with the findings of the 9/11 commission report, and Philip Zelikow, staff director of the commission, has noted that the panel had access to more material than the senator did.

After questioning Mr. al-Bayoumi, the commission concluded that he had no connection to the terror attacks.

The second Media Fund spot, entitled “All in the Family,” uses similar frames to the first spot, and the announcer intones: “The Saudi royal family. Wealthy, powerful, corrupt, and close Bush family friends. The Saudis have invested tens of millions of dollars in Bush business ventures. Rich Saudis bailed out George W. when his oil company went bust.”

The ad concludes: “Kind of makes you wonder.”

The Bush business venture in question is Harken Energy. A Bush official noted ironically that Saudis were not the only investors in the company. The billionaire George Soros, who has financed many of the Democratic 527s, also invested in the Texas business.