Acting on a tip-off, immigration officials descended upon the store in Headington, Oxford and arrested four Indian men.
One of the men was also arrested on suspicion of having a counterfeit Belgian passport and National Insurance card. He was charged with fraud and Identity Cards Act offences.
Another of the group has been granted immigration bail while the Border Agency obtains permission to remove him, and the other two are awaiting removal from the UK.
The store owner was served with a Notice of Penalty Liability informing him that he could be fined up to £10,000 per illegal employee unless he can prove that the correct right-to-work checks were carried out on the men.
Inspector Dick Stratton of the UK Border Agency said that other employers should be wary when it comes to illegal workers. "This operation should serve as a warning for those who break the law," he said.