(CNN) -- Mexican police freed a former American reality TV show producer from detention Friday but kept his passport so he couldn't leave Cancun while they investigate the death of his wife.
Bruce Beresford-Redman was taken into custody as a suspect in the death Thursday morning after Monica Beresford-Redman's body was found in a sewer at Cancun's Moon Palace resort, according to regional police spokesman Adrian Cardena.
The initial investigation suggested that she "died of strangulation, because of the bruising," Cardena said.
The couple and their children were staying at the resort when the husband, a former producer on CBS' "Survivor," reported her missing Tuesday.
A family friend said the couple had recent marital problems.
The wife had cleaned out the couple's bank account and traveled to Hawaii with her children last week after discovering that her husband was having an affair, the friend said.
CNN has not been able to confirm that any affair took place.
Bruce Beresford-Redman called his wife and convinced her to meet him in Cancun to reconcile their differences, the friend said. She arrived with the children last weekend, the friend said.
The family friend said the husband said in a phone conversation Wednesday that his wife disappeared after leaving their hotel room to shop.
Mexican police could not confirm any of these details to CNN.
Bruce Beresford-Redman's parents hired a public relations firm to help with the growing media inquiries about the investigation.
"We know our son loved Monica and would never have harmed her," they said in a written statement. "He has our full support as we try to do what's best for him and our grandchildren so they can be reunited soon."
The children flew back to Los Angeles to stay with relatives while the search for their mother was under way, a family source said.
The hotel issued a statement saying its employees helped police when they began their search Wednesday.
"We assure you that safety is always a top concern at Moon Palace Golf and Spa Resort, and our guests continue to be safe at this time," the hotel said.
Beresford-Redman built his career as a widely acclaimed Hollywood reality television show producer. He helped develop the popular 20-season CBS show "Survivor," in which contestants compete against each other in a variety of extreme outdoor scenarios.
He was nominated for three Emmys as a producer on the show but was last credited as a producer in 2004.
He also worked on NBC's "The Contender" and "The Restaurant" as well as MTV's "Pimp My Ride," according to entertainment media company IMG.
Monica Beresford-Redman, a native of Brazil, owned a restaurant in Los Angeles, California.
CNN's Mariano Castillo, Gabriel Falcon and Ninette Sosa contributed to this report.