Home Office officials are currently interviewing those detained during the raid to ascertain if they are working illegally.
A McAlpine statement said: “Sir Robert McAlpine can confirm that today the Home Office and Police officials attended Battersea Phase 3 project.
“Sir Robert McAlpine has and will continue to work in full cooperation on this case which involved a small number of individuals suspected of working in the UK illegally.
“Preventing the employment of illegal workers and ensuring ethical recruitment is of critical importance to the construction industry and Sir Robert McAlpine is resolute in its commitment in this regard.”
Chief Executive Paul Hamer said McAlpine would now be cracking-down on its supply chain as part of a “zero-tolerance” approach to illegal working.
Hamer said: “We have worked very hard to ensure all that we do as a business is in line with our values and of the highest ethical standards.
“Incidents such as today are a stark reminder that the industry still has much work to do.
“We take a zero-tolerance approach to such breaches and will be working with our supply chain to support further improvements. Construction activity at the Battersea site continued this morning.”
Construction is being targeted by the Home Office who staged a similar raid on BAM’s King’s Cross site last month.