Singer Britney Spears
, 26, who refused to turn over her two sons to her ex-husband Kevin Federline
was taken to a hospital by a Los Angeles Fire Department ambulance after police were called to her Studio City home in an attempt to resolve a custody dispute late Thursday night. According to LAPD spokeman, the 'Gimme More' singer was detained to evaluate what substance she was under the influence of when officers came to her Studio City home.