A terrified teenage boy who showed up at a Tracy gym begging for help had earlier been chained in a home and lived in filthy conditions as a captive, authorities said Wednesday.

Meanwhile, three people accused of playing a role in the alleged torture and kidnapping of the 17-year-old remained in custody and were expected to be arraigned in Stockton on Thursday.

"He was dirty. He was bloody," Tracy police spokesman Matt Robinson said Wednesday as he described the boy's ordeal, which by one account may have lasted nearly a year.

Robinson said Caren Ramirez was taken into custody by Tracy and Berkeley officers around 9:30 p.m. Tuesday at an apartment in the 2600 block of College Avenue in Berkeley.

Robinson added that the 43-year-old Ramirez is the boy's aunt.

The case started to unfold when the teen showed up at a fitness club called In-Shape City at 4 p.m. Monday with a chain locked to his ankle. He told gym personnel he had just fled his captors.

The boy was eventually taken to a hospital for treatment. He was discharged from the hospital on Wednesday and was turned over to child protective services workers.

Robinson was reluctant on Wednesday to offer more details about the boy's condition, adding that the investigation is still going on. Gym manager Chuck Ellis said the teen was scared someone was going to come after him and asked to be hidden.

"He said, 'Don't let them get me. Don't let them get me,'" Ellis said. "He was totally terrified."

The boy said he had been held captive for nearly a year, said Ellis, adding that he looked as if he was only 10 to 12 years old. Police had been looking for Ramirez after they arrested 30-year-old Kelly Layne Lau and 34-year-old Michael Schumacher.

Lau, a Girl Scout troop leader, and Schumacher are being held on bail of nearly $1.2 million each after being booked on suspicion of torture, kidnapping, false imprisonment, child endangerment and corporal injury to a child.

Investigators were trying to figure out the connection between the couple and Ramirez, who authorities believe occasionally visited their home.

Ramirez is expected to face the same charges as Lau and Schumacher.

Meanwhile, Lau and Schumacher's four young children, two of whom were home when police arrived, were taken into protective custody, authorities said.

Ramirez had become the teen's guardian after child-welfare officials took him from his abusive father three or four years ago, police said. After Ramirez was arrested on suspicion of abusing the boy, the youth was placed in another foster home, which he fled in late 2007, police said.

Since then, the boy's whereabouts hadn't been known until he entered the fitness center.