WASHINGTON - A TOP New York anti-terror official said on Tuesday that trials of Guantanamo Bay detainees could weaken the ability of the FBI and other agencies to chase new cases.

Richard Falkenrath, a New York Police Department official who was a homeland security expert in the Bush administration, said high-profile terrorism trials in the US could reduce the number of agents available to pursue new investigations.

Recently, the Justice Department brought suspect Ahmed Ghailani from the detention center at Guantanamo Bay, Cuba, to New York to face trial for Al-Qaeda attacks on US embassies in Africa.

Mr Falkenrath said that kind of decision 'is raising a lot of very difficult issues for investigators who now find themselves required to support these prosecutions'.

Typically, one or more FBI agents will be assigned to help prosecutors at trial, and in a large, complex terror case like Ghailani's, there can be months of additional work for many agents in and outside of a courtroom.

Such trials, Mr Falkenrath argued, will likely use up significant resources of the FBI, and possibly even the NYPD, since the two share resources on a joint terrorism task force.

He said the administration should 'watch out for' those cases draining resources from other investigations, although he said he is not against bringing such cases to federal court for trial.

While the two agencies work together every day on anti-terror cases, the NYPD and the federal government don't always see eye to eye on how to prevent terrorism or investigate suspects.

Ghailani's is the only such case so far, and it is unclear how many other Guantanamo detainees will be sent to courtrooms for trial.

Republican Senator Lindsey Graham has said he believes it will be 25 per cent or fewer of the remaining 229 inmates. That would still mean dozens of trials, whether in civilian or military settings. -- AP