A senior Pentagon official said Friday that defense lawyers in the case of five alleged al-Qaeda terrorists charged with plotting the Sept. 11, 2001, attacks should not have been questioned about their Internet browsing.

Ronald Bechtold, chief information officer at the Defense Department, told a military tribunal here that it “shouldn’t have happened,” but insisted that government officials were not watching attorneys’ computer activities when they used Defense Department systems.

Lawyers for the five defendants, who face charges of murder, terrorism and hijacking, are asking for planned military commission hearings to be suspended because of concerns about extensive computer problems. Technical difficulties have prompted allegations that large numbers of files have been lost, that e-mails have gone astray and that privileged defense documents were inadvertently passed to the prosecution.

David Nevin, the attorney for Khalid Sheik Mohammed, the self-professed mastermind of the attacks, suggested switching from monthly pretrial hearings to a bimonthly schedule to allow lawyers time to travel abroad in order to research the case, a move that could further delay already protracted proceedings.

On Wednesday, defense attorneys complained about “real-time monitoring” of their work on the Internet, saying their research staff had been contacted by unidentified government officials and questioned about search terms and about Web sites they had visited. Giving evidence Friday, Bechtold said he didn’t know the identity of the officials involved, but insisted he had taken steps to prevent such actions from occurring again.

Bechtold, who is leaving his post Nov. 1, said certain browsing had been automatically flagged by monitoring software and then passed to officials to investigate. He said he had been informed that someone had searched information used by the defense team for one of the defendants, Mustafa al-Hawsawi. “I’m really troubled by that. I don’t think that should have ever happened,” he said.

The chief information officer disputed other defense claims, including that privileged computer files had been lost, acknowledging only that there had been “data disruptions.”

He said there were fixes that could be implemented quickly, such as ensuring that defense
e-mails are encrypted and hiring a dedicated technician, that would address the lawyers’ concerns.

Bechtold said he was also prepared to consider putting the lawyers’ files behind a firewall on Defense Department systems, or implementing an independent server, solutions that would take several months.

It is unclear how much the proposed fixes will cost, but Bechtold told the court that one of two possible options would cost about $1 million more than the other.

It was revealed during the hearings that the United States expects to lay an underwater fiber-optic cable connecting the naval base to Florida within two years in order to improve Internet and telephone communications.