WASHINGTON — The Bush administration asked the Supreme Court Monday to throw out a lawsuit that seeks to hold federal agents responsible for driving an upstate New York computer software company out of business when the owner’s husband was mistakenly targeted in a child pornography investigation.

Douglas Hallward-Driemeier, an assistant solicitor general, told the justices that a 1946 law limiting lawsuits against the government and its employees was designed to protect ”the morale of the civil service.”

The court is being asked to decide the extent of government immunity and whether Susan and Richard Hallock can sue individual customs agents.

In 2000, customs agents learned about a Web site that was being used to display child pornography. A trace of the credit card used to pay the site’s subscription fee led the agents to Richard Hallock’s home in the village of Mohawk, 70 miles west of Albany.

What the agents didn’t know was that Hallock had been the victim of identity theft only a few months before, his business credit card stolen and used to set up the Web site.

The agents seized computers, software design files, software programming codes, client files and other material — all of which belonged to Ferncliff Associates, a computer software company owned by Hallock’s wife, Susan, through which Richard Hallock developed and sold software.

Several months later, the investigation was closed and no charges were brought against Richard Hallock. When the Hallocks’ computers were returned, the equipment was damaged beyond repair and they were forced to close Ferncliff Associates.

The Hallocks asked repeatedly over the years for copies of the hard drives that the Justice Department said the customs agents had made of the Hallocks’ computers and other property. The requests were denied.

”The loss of the computer data and source codes was fatal to Ferncliff Associates,” the Hallocks’ lawyers said.