Investigators have not released information on how much was taken or what part of the casino was robbed.
Someone robbed the Santa Ysabel Casino Monday and federal agents are investigating.
Limited information was released to the media by San Diego County Sheriff's Department.
The theft occurred Monday just after 8 a.m. in "a secured area of the casino" according to deputies.
Detectives have not released specific details including how much was taken.
The FBI and California Department of Justice have joined forces with San Diego Sheriff's Rural Law Enforcement Division who is leading the investigation.
The casino hosts a poker tournament from Thursday to Sunday every week.
Check back for updates on this developing story.