Police have arrested 58 people in connection with immigration offences during raids in the Edinburgh area.
Police and SDEA officers were involved in the raids
More than 10 addresses were targeted by Operation Underdo, which involved a multi-agency task force headed by the Scottish Drug Enforcement Agency.
Another three people suspected of taking part in "gangmaster activity" were detained, police said.
Detective Chief Superintendent Stephen Ward described the raids as a "true partnership operation".
"The UK Government is committed to tackling organised crime which is involved in the immoral activity of trafficking in human beings and those people who amass great wealth through the abject suffering of others," he added.
Eastern Europe link
More than 170 officers from Lothian and Borders Police, Customs and Excise and the UK Immigration Service took part.
The three suspected gangmasters are from Scotland and the suspected illegal immigrants are mainly from former eastern European countries and Russia.
A Home Office spokesman said: "The successful operation is an excellent example of cross-government working and clearly demonstrates the good working relationships and dedication of all those involved in this multi-agency task force.
"This is one example of the sort of intelligence-led operations the Immigration Service undertake up and down the country every day and demonstrates the government's commitment to dealing with the issue of illegal working."