The first deportations have taken place after nearly 60 workers were arrested at a Shropshire factory during a raid by police and immigration officers. They targeted Epson's Hortonwood factory in Telford on Tuesday after a tip-off from the company.
One person has been flown to Guyana and another two to Ghana. Twenty-seven other people are awaiting deportation.
The Home Office said another worker was detained as he arrived at the printer cartridge company on Wednesday morning.
About 50 police and immigration officers have been involved in Operation Geomancy, which has been running for several months.
The Home Office says 31 illegal immigrants and three dependents, children under 16, have been found as part of the operation.
Fake passports described as "sophisticated" have also been seized.