An unpaid bill of about $775,000 left over from the Par Ridder saga of 2007 sparked a new lawsuit this week in Hennepin County District Court, with a computer expert claiming that a law firm never paid him for storing vast amounts of computerized evidence in the case that pitted the Twin Cities' two major newspapers against one another.

Mark Lanterman said the cost of storing 62 terabytes of Star Tribune data, enough that if it were published on CD-ROMs would stack up higher than a 30-story building, came to $155,000 per month. He said he stored the data for five to six months before deleting it.

Lanterman, who runs Computer Forensic Services out of an office in Minnetonka, said in a lawsuit filed Tuesday that he's owed the money by Leonard, Street and Deinard, the Minneapolis law firm the St. Paul Pioneer Press retained after Ridder joined the Star Tribune as publisher.

A Ramsey County District Court judge concluded that Ridder shared confidential data from a Pioneer Press laptop with Star Tribune colleagues, leading to Ridder's departure as publisher of the state's largest newspaper.

The lawsuit says Computer Forensic Services stored the data it culled from Star Tribune computers from August 2007 until Jan. 22, 2008. The firm charges $2.50 a gigabyte per month, the suit says.

In a reply filed Wednesday, Lowell Noteboom, a lawyer for Leonard, Street and Deinard, said the firm doesn't plan to pay the bill. A contract with the computer expert was never signed, he wrote, and the invoice came too late for the firm to bill it to the Star Tribune, which was ordered by the court to pay the Pioneer Press' legal fees and expenses.

Noteboom concluded his reply by listing 15 reasons the computer firm's lawsuit should be dismissed, including that the firm was paid "handsomely" for every invoice handed in on time, an amount that came to $854,068.71.

Matt McKinney • 612-673-7329