Floyd Mayweather Jr. is being sued over statements accusing Manny Pacquiao of taking performance-enhancing drugs. ((Jesse D. Garrabrant/NBAE via Getty Images) )

Superstar boxer Floyd Mayweather Jr. was a no-show for a court-ordered deposition in Las Vegas on Friday in a federal lawsuit alleging he defamed rival fighter Manny Pacquiao, Pacquiao's lawyer said.

Lawyer Daniel Petrocelli said Mayweather violated a court order by not appearing to answer questions about repeatedly saying Pacquiao has used performance-enhancing drugs. Petrocelli said he plans to ask a federal judge to rule in Pacquiao's favour as a result.

"We will seek a default. The court has the power to hold him in contempt as well," Petrocelli told The Associated Press. "He has an obligation to respect the process and to follow a court order."

Mark Tratos, Mayweather's lawyer, said he filed an appeal to the order Thursday evening that is still pending, and told Pacquiao's lawyers that neither he nor the fighter were available Friday morning.

"We tried to extend every courtesy we could," Tratos said.

Both sides argued Thursday before federal Magistrate Judge Robert Johnston, with Johnston siding with Pacquiao. Mayweather's side argues he needs to concentrate on training for a Sept. 17 fight against Victor Ortiz.

Tratos said he planned to file with the court on Monday a copy of Mayweather's training regimen, to show why it can't be interrupted as he looks to fight for the first time in more than a year.

"We're more than happy to produce him after the fight," Tratos said. "It's important for him to be in tip-top shape."

Tratos said he expected a deposition would take about seven hours, but would require time for Mayweather to prepare.

Mayweather and Pacquiao are considered by many the best pound-for-pound fighters in the world, though they've never met in the ring. Negotiations for a megafight that would presumably sell out, draw a huge pay-per-view audience and make each fighter millions have fallen through several times.

Pacquiao (53-3-2), the current WBO welterweight champion, is scheduled to fight in November against Juan Manuel Marquez. Mayweather is undefeated in 41 fights, having won titles in five divisions.

Pacquiao's suit was first filed in 2009, alleging Mayweather and his camp maliciously said in interviews that Pacquiao had gained his strength and power using illegal drugs. Pacquiao says in the suit that he has never tested positive for any performance-enhancing drugs.

Mayweather's lawyers have said in the past that Pacquiao's rival was merely questioning the boxer's reluctance to submit to strong drug testing -- stopping short of calling him a drug user.

Tratos said Friday that view has not changed.