Police authorities said that a Tracy couple was jailed today on suspicion of kidnapping, torture, false imprisonment and child abuse, after an emaciated, terrified and nearly naked 17-year-old appeared at the In-Shape Sports Club in Tracy on Monday, with a chain locked to his ankle, saying he had just fled his captors. The authorities said the boy, whose name was not released, ran away from a Sacramento foster home last year.

Gym manager Chuck Ellis said the boy, who looked as if he was only 10-12 years old, came into the gym wearing only boxer briefs and covered in soot. Ellis said the teen was scared someone was going to come after him and asked to be hidden.

Tracy police spokesman, Matt Robinson, the police arrested Michael Luther Schumacher, 34, and Kelly Layne Lau, 30, after questioning them, and finding further evidence implicating them. They were each being held in lieu of $1.1 million bail at San Joaquin County Jail. Authorities said the couple has four children, who have been placed with social service workers.

Police said a third suspect, 43-year-old Caren Ramirez, the boy’s aunt, is being sought in connection with the alleged abuse and a felony warrant for an earlier incident of beating the boy. Robinson said Ramirez had become the teen’s guardian after child-welfare officials took him from his abusive father about four years back. After Ramirez was arrested for allegedly abusing the boy, he was placed in another foster home, which he fled in late 2007.

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