OTTAWA -- Information the RCMP passed to U.S. officials in sloppy fashion was used in a hearing that resulted in Ottawa engineer Maher Arar's deportation to Syria, where he was imprisoned for months as a terrorism suspect.

The admission comes in an internal report by the Mounties in which the police force acknowledges it lacked the know-how to handle national security probes following the Sept. 11, 2001 terrorist hijackings in the United States.

"At that time, both at headquarters and in the field, the RCMP did not have sufficient investigative expertise, nor did they have the capacity to efficiently and effectively deal with national security investigations overall," says the report.

A declassified version of the top secret document was made public Monday by the federal commission of inquiry into Arar's case.

It was prepared by RCMP Chief Supt. Brian Garvie in response to an earlier probe by the Commission for Complaints Against the RCMP, the force's independent watchdog.

The report confirms Arar was a "person of interest" to security investigators in both Canada and the United States from at least late 2001 onward.

Arar, a Syrian-born Canadian citizen, was detained in New York in September 2002 as an alleged member of Osama bin Laden's al-Qaida network.

The Ottawa telecommunications engineer was travelling on a Canadian passport when U.S. authorities jailed him, then deported him to Syria.

The 35-year-old Arar says Syrian officials tortured him in a grim cell before he was set free several months later. He denies any involvement in terrorism.

The report indicates that while U.S. authorities first learned of Arar from the RCMP, they held him in New York on the basis of information gleaned not only from the Mounties but also from their own investigation of the Ottawa man.

Both the RCMP and U.S. officials were interested in Arar's apparent links to other suspected al-Qaida members or associates, including Abdullah Almalki, who was also imprisoned in Syria.

The report says U.S. authorities asked the RCMP to provide information that might help them file criminal charges against Arar.

One Mountie quoted in the document says the inability of U.S. officials to pursue charges is "the most plausible reason for his subsequent deportation."

In comparison to a previously released summary, the report paints a much more critical picture of the RCMP's handling of sensitive data about Arar.

It indicates "all available information" obtained by the RCMP under Project A - O Canada, the force's anti-terrorism investigation in the national capital region, was shared with U.S. officials.

Without providing specifics, the report refers to a number of instances in which material was passed along without proper regard for required caveats and conditions about its use.

"This allowed U.S. agencies to use, or disseminate, that information as they deemed appropriate, without the express permission of the RCMP."

In at least one instance, "the reliability assessment of that information was inaccurate."

The report adds: "Information provided by the RCMP was used in (the) hearing that resulted in Maher Arar's deportation to Syria."

No additional details about the material are provided.

However, the report found no evidence that any RCMP member influenced the U.S. decision to deport Arar to Syria, and the decision was made unilaterally by U.S. authorities.

The document also says the Mounties did not contribute in any way to the torture or interrogation of Arar in Syria.

However, the report shows the RCMP balked in June 2003 when Foreign Affairs officials wanted to send Syria a letter from their minister saying there was no evidence Arar is involved in terrorist activity.

A senior Mountie protested, saying Arar was the subject of a "national security investigation" and remained "a subject of great interest."

Arar expressed dismay Friday at the revelation.

"I could have been out of that miserable place four months earlier," he said in a statement.

Arar said he was also surprised to learn from the report that his apartment lease, which linked him to Almalki, was obtained from his landlord, Minto Developments Inc., without a warrant.