A lack of adequate computer security in the Department of Justice is endangering highly sensitive information, ranging from identities of confidential informants to undercover operators, congressional investigators have concluded.

Although the department moved its main data center last year to a new "state-of-the-art" facility, unauthorized users still could enter and exit the system without being detected, the General Accounting Office said in a report to be issued soon.

"The threat of intrusion into these systems is serious, and there are criminals who could benefit immensely from such covert encroachments," Rep. Robert E. Wise Jr. (D-W.Va.) said in a letter urging Attorney General Dick Thornburgh to "immediately correct" the security flaws.

Wise, chairman of the House Government Operations subcommittee on government information, justice and agriculture, asked for the study in July after an earlier GAO examination of the Department of Justice's office automation systems turned up security concerns.

A department official who requested anonymity said he was dismayed that the GAO assessment failed to cite "a lot of corrective action already taken and more that is under way."

The official, who is involved in the work, said the data center was moved from downtown Washington to a suburban Maryland location before security equipment had been installed because of fire and safety concerns at the older facility. A dispute between bidders has held up purchase and installation of security equipment, he said.

But the GAO examination described a broader set of problems, citing "many disturbing weaknesses in existing security which, if not corrected, could severely compromise both the computer systems and the sensitive information they process."

In a directness unusual for a GAO document, a copy of which was provided to the Los Angeles Times, the report blamed the security weaknesses on "a lack of effective leadership and oversight by the Justice management division," which is headed by Assistant Attorney General Harry H. Flickinger.

"If that reference is meant as a personal attack, there's no reason for it," said Daniel G. Eramian, the department's deputy director of public affairs. "If what they mean is that we lack review or audit {of computer security}, we have requested additional resources from Congress for that and have not received them."

The report focused on computer security programs in the department's litigating units, which include 94 U.S. attorney offices around the nation and six divisions in Washington: antitrust, civil, civil rights, criminal, land and environmental protection and tax.