Five of the workers have been detained and placed in Villawood detention centre in Sydney, pending their deportation.

Four others have been given bridging visas until they leave the country.

One other was given a notice of the department's intention to cancel their visa.

Eight of those questioned were Chinese nationals, with one Thai and one South Korean man also questioned.

All of those transported to Villawood were Chinese nationals.

The nine men and one woman were working at a site at the corner of Ginninderra and Aikman drives, with most of them involved in tiling and plastering work.

Officials from the Department's ACT office conducted the raid at about 11am yesterday.A spokesman for the Department of Immigration and Citizenship said seven of the workers were ''unlawful citizens'' without a visa, while three others were working in breach of their visa conditions.

The building site is operated by St Hilliers Group, but The Canberra Times understands the 10 workers were employed by three separate sub-contracting groups.

''The company who was running the site has fully co-operated with the department and has had nothing to do with employing the people located during the operation,'' a Department of Immigration and Citizenship spokesman said.

All three sub-contracting firms would be issued with an illegal workers' notice.

The spokesman said any company concerned about their workers' visa status should check with the department.

''We're always making appeals for employers to check work rights, which can be done online,'' he said.

Representatives from St Hilliers Group did not return calls.