A federal judge expressed reservations Friday to granting a request by the defense lawyers for Alec and Michael Sou of Aloun Farms to have the federal government pay their attorney fees and costs to defend themselves against forced-labor charges that prosecutors dropped during the trial.

The Sous’ attorneys estimate the amount to be close to $500,000.

Chief U.S. District Judge Susan Oki Mollway heard arguments on the defense motion and said she will rule later.

But she said it was "very difficult" for her to find that the government’s case was so "frivolous" to warrant the granting of the fees and costs when the Sou brothers had earlier pleaded guilty to a forced-labor charge.

The Sous withdrew their guilty pleas, clearing the way for the trial that ended Aug. 4 when government lawyers dismissed the case "in the interest of justice."

If Mollway grants the defense motion, another hearing will be held to determine the amount of fees and costs.

The request by the Sous’ attorneys, Thomas Bienert of San Clemente, Calif., and Thomas Otake, is based on federal law that permits the defense to recover fees and costs when the government’s prosecution was "frivolous" or groundless with little chance of success.

The Sous were charged with forced labor and related counts involving 44 Thai workers who paid as much as $20,000 to Thai recruiters to work at Aloun Farms in 2004 and 2005.

In 2010 the Sous entered a plea agreement but withdrew their guilty pleas after Mollway rejected the deal. She ruled that the Sous’ admissions did not go far enough to support their guilty pleas.

On Aug. 4, four days after their trial opened in Mollway’s courtroom, federal prosecutors dismissed all charges against the Sous.

The move came after civil rights lawyer Susan French acknowledged that she had misstated before the federal grand jury that the recruitment fees were illegal.

She dropped out of the case later that day for health reasons.

Bienert argued Friday that the prosecution was based on a "faulty premise of law" that recruitment fees were illegal and the government did not have evidence to show the Sous coerced any of the workers to remain on the job.

Kristy Parker, Justice Department civil rights attorney, disputed that the legality of the fees was central to the prosecution.

She argued that the government’s case alleged that the Sous coerced the laborers to work at the Sous’ Kapolei farm under threat of economic harm if they did not remain on the job, regardless of the legality of the fees.

She said the government had statements from witnesses, including the workers, to support the charges.

Bienert’s points went to the issue of whether the Sous were guilty and not whether the charges were frivolous, Parker argued.