Two men working in a Costcutters near Westminster face deportation after immigration officials discovered they had "overstayed their visas".
Officers went to the shop in Royal Oak, Harrow Road at around 10.15pm on Wednesday (August 26).
Shop staff were asked whether they had the right to live and work in the UK.
According to the Home Office, two men from Pakistan, aged 27 and 31, were arrested after it was found they had overstayed their visas.
Both were transferred to immigration detention pending removal from the UK, the Home Office said.
The business was served a notice warning that a financial penalty of up to £20,000 per illegal worker arrested will be imposed unless the employer can show proper checks were carried out such as seeing a passport or Home Office document.
Immigration Minister James Brokenshire said: “Anyone who thinks the UK is a soft touch should be in no doubt – if you are here illegally, we will take action to stop you from working, renting a flat, opening a bank account or driving a car.
“Through our new Immigration Bill, illegal workers will face the prospect of a prison term and rogue employers could have their businesses closed, have their licences removed, or face prosecution if they continue to flout the law.”
The Immigration Bill, due to be introduced this autumn, will include new powers to deter people from trying to find work illegally and measures to deal more effectively with businesses who flout the rules.
A new criminal offence of working illegally will mean offenders could face a prison sentence of up to six months and their wages seized as proceeds of crime.
