Saudi Arabia has denied allegations that it helped finance two of the hijackers involved in last year's 11 September attacks on the United States.

Nail al-Jubeir, an aide to Saudi Arabia's de facto ruler Crown Prince Abdullah, said reports that the wife of the Saudi ambassador to America sent money to the hijackers were "untrue and irresponsible".

[Princess Haifa al-Faisal] wants her name cleared

Nail al-Jubeir, Saudi spokesman

Members of a US congressional committee probing the attacks have accused the Federal Bureau of Investigation (FBI) of not examining claims of a link between the Saudi Government and the hijackers closely enough.

According to US media reports, the two hijackers - Khalid al-Mihdhar and Nawaf al-Hazmi - received $3,500 a month from two students in the United States via an account in the name of Princess Haifa al-Faisal, the Saudi ambassador's wife.

Mr al-Jubeir said the money did not come directly from the princess.

"She wants her name cleared," he said.

US National Security spokesman Sean McCormack said on Saturday it was too early to jump to conclusions about the suspected money trail.

'Ulterior motive'

Mr al-Jubeir voiced surprise that the committee was investigating the possible existence of the money, saying he thought the issue was closed several months ago.

Most of the hijackers were Saudi

He said he believed that "the people who are behind this are more interested in scoring political brownie points than they are in arriving at the truth".

The Saudi official said his government was working closely with the United States and continued to "mercilessly" pursue suspected members of the al-Qaeda terror network.

Relations between the US and Saudi Arabia have cooled since last year's attacks.

Fifteen of the 19 hijackers were Saudi citizens, and many American commentators have accused the Saudis of funding Muslim militant groups.

Intelligence 'failings'

The New York Times newspaper says a draft report by the congressional committee has concluded that the FBI and the CIA have not pursued aggressively enough leads that might link the hijackers to Saudi Arabia.

The two agencies have disagreed with the draft findings, saying they have been investigating all relevant information, the paper says.

The New York Times quotes a reply by the FBI to the committee, arguing that it was common for Saudis in the United States to receive financial support from their government.

The FBI also says an inquiry into the two students - who have since left the country - failed to produce evidence that they had links to the attacks, according to the paper.

There has been tension in the past between intelligence agencies and the congressional committee investigating the attacks.

A number of interim reports released in recent months have highlighted apparent intelligence failures.