IRS agents served a search warrant Tuesday at a popular La Mesa eatery.
Customers were still being served at the Lake Murray Cafe after the agents arrived.
NBC 7 reached out to the restaurant's management, but they declined to talk to us.
The warrant was served by a group that is part of the federal agency's criminal investigation unit.
The IRS has not yet said why it is investigating the restaurant, but we will bring you more details once the investigation is complete.