EXCLUSIVE - A Saudi Arabian linked to one of the September 11 hijackers spent four months in New Zealand before being expelled as a national security risk.

The United States-qualified pilot, Rayed Mohammed Abdullah Ali, was admitted to New Zealand in February on a student visa, saying his dream was to become a commercial airline pilot and that he needed an English language qualification to assist.

Today the Weekend Herald reveals that on May 29 police and immigration officials raided Ali's Palmerston North home and deported him.

The 28-year-old had recently moved there from Auckland, partly to fly at the Manawatu Aero Club.

A Government statement to be released this morning will confirm that Ali was deported because he "posed a threat to national security".

The Government claimed last night that Ali had lived and trained in Phoenix, Arizona, with fellow Saudi Hani Hanjour in the months before Hanjour is believed to have piloted American Airlines Flight 77 into the Pentagon building.

It is only the second time that section 72 of the Immigration Act has been used to deport someone. Its use requires the consent of the Governor-General, and there is no right of appeal.

Police seized Ali's flight logbook from the aero club, where he had flown several times in Cessna aircraft accompanied by instructors. He was sent back to Saudi Arabia under escort.

Immigration Minister David Cunliffe said last night Ali was considered a threat to national security because of his direct association with those responsible for the 2001 terrorist attacks, the nature of his activities in the US before then and the nature of his activities in New Zealand.

The Weekend Herald has learned he spent most of his time in Auckland attending an English language course but shifted to Palmerston North early last month, planning to enrol in another English course and increase his flying hours.

The case raises questions about New Zealand's security intelligence and border control mechanisms.

Mr Cunliffe said Ali's true identity became apparent only after he arrived in New Zealand - "he used a variation of his name in applying for entry".

But the Weekend Herald has been told the only variation on his passport was the use of the initial A for Abdullah, and that was corrected in a note inside the passport.

The minister referred the Weekend Herald to excerpts from the US Government's 9-11 Commission Report on the attacks regarding "Rayed Abdullah".