Attorneys who accuse Greg Mortenson of defrauding readers in his best-selling Three Cups of Tea say his case is no different from that of James Frey, who admitted on the Oprah Winfrey Show that he lied in his memoir A Million Little Pieces.

That lawsuit ended in a settlement that offered refunds to buyers of the book.

Mortenson has asked a U.S. judge to throw out the civil lawsuit that says he fabricated portions of his book, saying that if it is allowed to proceed, other authors could be subjected to similar claims and the result would be a stifling of the free exchange of ideas.

"Plaintiffs should not be allowed to create a world where authors are exposed to the debilitating expense of class action litigation just because someone believes a book contains inaccuracies," attorney John Kauffman wrote in the filing late last month.

But the plaintiffs' attorneys argue in court documents filed Tuesday the lawsuit should go forward because of the precedent set by class-action lawsuit against Frey. The two cases are "nearly identical," they said.

"The facts in the [Frey] case are stunningly close to the facts in this case, but not nearly as compelling," wrote attorney Alexander Blewett.

The lawsuit claims Mortenson lied about how he began building schools in Pakistan and Afghanistan and fabricated other events in the books Three Cups of Tea and Stones Into Schools. The attorney who led the Frey lawsuit, Larry Drury, is also a plaintiffs' attorney in the nine-month-old case against Mortenson.

Winfrey show admission

Winfrey chose A Million Little Pieces, for her book club in September 2005, boosting its sales, which eventually topped 3.5 million. But then Frey acknowledged on Winfrey's show in January 2006 that he had lied in the memoir of addiction and recovery.

A judge in 2007 certified a class-action lawsuit by disgruntled readers against Frey, and the resulting settlement offered a refund to anybody who bought the book before the falsehoods were acknowledged.

Only 1,729 people asked to be reimbursed, costing Random House $27,348 US. The attorneys in the case were paid $783,000 US in fees.

Haddon has not yet scheduled a hearing on whether to dismiss the claim against Mortenson.

The lawsuit accuses the Montana resident of being involved in a racketeering scheme to turn him into a false hero, defraud millions of people out of the price of the books and raise millions in donations to the charity. The other defendants allegedly in on the scheme are co-author David Relin, publisher Penguin Group and Mortenson's Bozeman-based charity, Central Asia Institute.

Mortenson's accusers seek reimbursement of all the money that was made from his books. The lawsuit has been amended four times, with a changing cast of plaintiffs who now number four.

60 Minutes revelations

The lawsuit was filed a few weeks after author Jon Krakauer and 60 Minutes revealed in April 2011 discrepancies in Three Cups of Tea and questioned whether Mortenson was benefiting from his charity.

Meanwhile, Montana prosecutors are moving ahead with their own investigation into Mortenson's charity, saying they plan to update the public about the investigation in the next few weeks.

The Montana attorney general's office is investigating whether the Central Asia Institute broke any laws that govern non-profits in Montana. Assistant Attorney General Jim Molloy said investigators have reviewed thousands of pages of documents and interviewed Mortenson and others connected to the charity.

He declined to say what the investigation has revealed but said his office would be updating the public within a month. The state's probe does not involve the merits of the accounts contained in Mortenson's books, he said.

Mortenson has denied wrongdoing and has kept out of the public eye since having heart surgery last year. In December, the Central Asia Institute said in its year-end letter that Mortenson would no longer be involved in the charity's day-to-day management and that it was looking at expanding its three-person board of directors.