Los Angeles, California (CNN) -- The sisters of a Los Angeles woman found dead in Cancun, Mexico, in April want the U.S. government to explain why her husband has not been arrested a month after Mexican prosecutors requested his extradition.

"We are tired of waiting," Jeanne Burgos said Thursday. "It's not fair."

She and her sister Carla Burgos staged a rally outside the federal courthouse in downtown Los Angeles on Thursday afternoon to demand an arrest.

"We are demanding that the United States authorities just do what they have to do," Burgos said. "We are not asking for anything beyond what their duties are."

Reality TV producer Bruce Beresford-Redman is still living free with his children in Los Angeles nearly two months after a Mexican judge ordered his arrest. Mexican officials said June 23 that they had sent their extradition petition to the U.S. Embassy in Mexico City.

Neither the U.S. State Department nor the Justice Department in Washington would confirm what has happened with the extradition request. A spokesman for the U.S. attorney in Los Angeles, who would pursue an arrest, said Thursday that nothing has been filed in California.

"They are not telling us anything," said Allison Triessl, the Burgos family's lawyer. "We have repeatedly asked. We have made phone calls almost daily, and we have received no information at all."

Beresford-Redman was briefly detained after his wife's body was found April 8 in a sewer at Cancun's Moon Palace Resort. His passport was taken by investigators, and he was told not to leave Mexico until the inquiry was concluded.

Quintana Roo state Attorney General Francisco Alor said in May that he has a "very concrete" case against the former "Survivor" producer.

Beresford-Redman's lawyer, Richard Hirsch, has said he would fight extradition.

Beresford-Redman returned home in May, without the knowledge of investigators, to take care of family business and see his two young children, his lawyer said.

His parents have temporary legal custody of the children, ages 3 and 5, but they are staying with Beresford-Redman.

The initial investigation suggested that Monica Beresford-Redman "died of strangulation, because of the bruising," Mexican regional police spokesman Adrian Cardena said.

A source close to the wife has said that she cleaned out the family's bank account and took her two children to Hawaii because she was upset about her husband's extramarital affair. The couple later traveled to Cancun in an effort to repair their marriage, the source said.