Ex-NBA Player, Girlfriend Vanish in South Pacific

A former NBA star and his girlfriend have not been heard from since July, but family members today told ABCNEWS' Good Morning America they were clinging to the hope the couple would be found alive.

Bison Dele, 33, who was known as Brian Williams during his basketball career, and his girlfriend Serena Karlan, 30, were last heard from in July.

Dele, who played both center and forward, was with a number of teams during his career, including the Denver Nuggets, the Los Angeles Clippers and the 1997 NBA champion Chicago Bulls. Most recently, from 1997-99, he played for the Detroit Pistons.

After Dele walked away from a $35 million contract in 1999, he went to Lebanon to join friends in a water purification business, but later moved to Australia, and took up a carefree life that included motorcycling and surfing.

On July 4, Dele went off on a sailing adventure in the South Pacific. But now he is missing, along with the captain of his sailboat, Bertrand Saldo, and Karlan, his girlfriend of seven months. The group set sail from Moorea, Tahiti, and were headed to Hawaii via the remote Tuamoto and Marquesas Islands in the South Pacific.

Without a Trace

Family members, who have not heard from Dele or Karlan since July 8, reported them missing at sea and Karlan's parents said authorities had told them the case is now being treated as a murder investigation.

"In August, it was sort of a gradually mounting concern — I felt like something needed to be looked into," Gael Ohlgren, Karlan's mother, told ABCNEWS' Good Morning America.

Karlan's stepfather, Scott Ohlgren, says they are desperate for answers.

"You kind of get numb after a while," Ohlgren said. "You can only stay grim for so long and then …"

Dele's 55-foot catamaran was found abandoned late last week in a harbor in Tahiti. It had been repainted and renamed. The FBI has issued an arrest warrant for Dele's brother, Miles Dabord, who had been with his brother and the group until the he flew back to the United States several weeks ago.

Foul Play?

Dabord left the boat in Tahiti and returned to the United States in early July. But no one has heard from the other three, and now both the FBI and police suspect foul play.

Police say Dabord showed up at a Phoenix high-rise in August and tried to pass himself off as Dele to buy $152,000 in gold. A Phoenix police report shows Dabord was rejected because of forgery, and that he used his brother's passport and credit cards. He was questioned by police but never arrested.

"They didn't feel they had sufficient evidence to take him into custody," said Laurel Williams, a spokeswoman for the Phoenix Police Department.

Scott Ohlgren says the police have done everything in their legal power to hold onto Dabord.

"Those guys did everything they could, they were calling judges, they were calling the FBI, and none of them could tell them for certain, yes, you can hang on to Miles [Dabord]," Ohlgren said.

Dele had been friends with Karlan for years before they began dating. She was living in New York when he asked her travel with him last year. Karlan's mother said the couple had a good relationship.

— ABCNEWS' Bill Redeker contributed to this report.