(Bloomberg) -- The agency that manages U.S. government personnelrecords shut down the online system used to conduct backgroundchecks, three weeks after officials disclosed a cyber-attack thatstole data on as many as 18 million people.

The Office of Personnel Management said Monday that itsElectronic Questionnaires for Investigations Processing system, ore-QIP, was temporarily suspended for four to six weeks because of asecurity flaw.

The e-QIP’s Web-based system is used to conduct backgroundchecks for more than 100 federal agencies, according to the OPM’swebsite.

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“This proactive, temporary suspension of the e-QIP system willensure our network is as secure as possible for the sensitive datawith which OPM is entrusted,” OPM Director Katherine Archuleta saidin the statement.

The agency said there is no evidence that the security flaw hadbeen exploited by hackers. It was found as a result of acomprehensive security assessment in the wake of thehacking attack first revealed June4.

A telephone call and e-mail to OPM seeking more informationabout the shutdown weren’t immediately returned.

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The e-QIP system allowed those seeking security clearances toelectronically file a 127-page form that requires sensitiveinformation, including Social Security numbers.

“These are people who have sensitive information, and we drilldown on these folks,” said Representative Stephen Lynch, a Democratfrom Massachusetts, in a House Oversight Committee hearing June 16.“We ask them everything.”

Lawmakers called for the resignation of Archuleta after shetestified before a congressional committee last week.

U.S. Director of National Intelligence James Clapper said at aconference last week that China is a “leading suspect” in thehack.

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