THE 200 foreign workers who gave blood samples to police officers investigating a sexual assault case in Clementi did so voluntarily, and were not forced.

In a written reply to a question from Non-Constituency MP Sylvia Lim, Home Affairs Minister Wong Kan Seng on Monday explained that samples taken from foreign construction workers after the June 18 incident in Clementi Woods Park were obtained with the workers' consent.

Ms Lim had asked for the legal basis for taking the samples.

Mr Wong pointed to provisions under the Registration of Criminals Act, which stipulates that someone being questioned in connection with a crime, or who was present at the scene when the crime was committed, may give a body sample on a voluntary basis.