WASHINGTON (AP) — Hackers linked to China have gained access to the sensitive background information submitted by intelligence and military personnel for security clearances, U.S. officials said Friday, describing a cyberbreach of federal records dramatically worse than first acknowledged.

The forms authorities believed may have been stolen en masse, known as Standard Form 86, require applicants to fill out deeply personal information about mental illnesses, drug and alcohol use, past arrests and bankruptcies. They also require the listing of contacts and relatives, potentially exposing any foreign relatives of U.S. intelligence employees to coercion. Both the applicant's Social Security number and that of his or her cohabitant is required.

"In a statement, the White House said that on June 8, investigators concluded there was "a high degree of confidence that ... systems containing information related to the background investigations of current, former and prospective federal government employees, and those for whom a federal background investigation was conducted, may have been exfiltrated."

"This tells the Chinese the identities of almost everybody who has got a United States security clearance," said Joel Brenner, a former top U.S. counterintelligence official. "That makes it very hard for any of those people to function as an intelligence officer. The database also tells the Chinese an enormous amount of information about almost everyone with a security clearance. That's a gold mine. It helps you approach and recruit spies.