LOS ANGELES -- Investigators who found apparent blood traces on the sailboat of Bison Dele suspect the former NBA player and two others were murdered by his brother.

Authorities searching Dele's 55-foot catamaran at a Tahitian port discovered traces of what appeared to be blood inside and outside the vessel, said Michel Marotte, Tahiti's chief prosecutor.

The findings must be verified in a laboratory "but it does seem to be blood traces,'' he told The Associated Press on Friday.

Dele's brother, Miles Dabord who is also known as Kevin Williams, was in a coma and in critical condition at a hospital in Chula Vista. He was found unconscious in Mexico last week. The FBI arrested him Thursday on a fraud charge after learning his identity. Dabord allegedly used his brother's former name, Brian Williams, while trying to buy $152,000 in gold in Phoenix earlier this month.

Dabord's mother, Patricia Phillips, told the Los Angeles Times she fears her son may have tried to commit suicide in a fit of guilt, somehow believing he was responsible for his brother's disappearance. On Friday, she stood at his bedside in a San Diego hospital.

"I wanted to hug him, to stroke his face, to hold his hand,'' she said.

In a Sept. 13 telephone call, Phillips said Dabord sounded groggy and spoke of committing suicide. He told her he hadn't killed his brother and that he wanted her to know this before ending his life, she said.

FBI agent Josephina Regula said Dabord had no apparent external injuries when he was found on a beach next to the U.S. border fence. Regula said she had no information on the cause of the coma.

Dele, 33, changed his name from Williams during an NBA career in which he played for several teams, including one of the Chicago Bulls' world championship squads. The free-spirited center walked away from a $35 million contract with the Detroit Pistons in 1999, at age 30.

Marotte said there is reason to think that Dele, his 30-year-old girlfriend Serena Karlan and Bertrand Saldo, the captain of Dele's sailboat, were killed July 6 or 7 during a layover in Tahiti.

Investigators are working on the suspicion that a single person committed the killings, and "that is the brother of the victim, Kevin Williams.''

"We presume that the bodies of these people must be in the sea, the ocean, and will probably never be found,'' said Marotte, who speculated that the bodies could have been weighted down to sink them. "But we're still looking.''

FBI agents who have been going over the boat since Tuesday found what may be traces of patched holes. Investigators are trying to determine whether the holes "might reveal the use of a weapon, of a bullet,'' Marotte said.

Dabord was traveling with Dele and his party on a trip from New Zealand to Hawaii. Investigators suspect an argument broke out on board as the boat was in deep water between Tahiti and one of the islands near the French territory.

On Sept. 5, Dabord was briefly taken into custody in Phoenix after allegedly attempting to buy $150,000 in gold using his brother's identification. A week later, the sailboat was found in Tahiti, with a new name. That same day, Mexican authorities found a hotel room in Tijuana where Dabord had been staying. Dabord was found unconscious two days later.