Immigration officers and police have arrested more than 100 illegal foreign workers at a biscuit factory.
The biscuit factory owner could be fined more than £500,000
Fifty officers raided the premises of the Cookie Man Ltd in Esher, Surrey, on Monday, the Home Office said.
The factory owner could face a fine of more than £500,000 after the intelligence-led operation, a a Home Office spokeswoman said.
Of 175 people at the factory, 101 were found to be foreign nationals working illegally.
Health and safety abuses
They were being held on Tuesday at police stations across the South East for offences including entry without leave, working in breach and overstaying their visas, the spokeswoman said.
The 101 arrested people includes 68 Brazilians, 17 Ukrainians and seven Lithuanians.
"In due course arrangements will be made to remove them from the UK," the Home Office spokeswoman said.
Officers were also considering whether to prosecute the factory owner, who could face fines of £5,000 for each illegal worker, she added.
Home Office minister Fiona Mactaggart said she was delighted with the operation's success.
She said: "Illegal working creates a pull factor for illegal migrants to the UK, undermines legitimate business competition and can lead to abuses of health and safety - this is why it is damaging to the economy as a whole.
"We have recently introduced new powers for immigration officers in order to enhance their effectiveness.
"However, simply increasing enforcement activity alone will not solve this problem.
"We are also working closely with employers to ensure that they comply with their legal obligations to check that new staff have the right to work in the UK."