
In a statement, the Immigration Department said those detained were part of 101 workers inspected at a construction site on Jalan Seri Tanjung Pinang, where two blocks of serviced apartments are being built.
They comprised 46 Bangladeshis, 22 Myanmar nationals, 15 Indian nationals and four Indonesians.
Fifteen other foreign workers, including two from China, were found to be legally employed.
The department said those detained were found to have entered the country without valid passes, possessing expired passes or violating the conditions of their entry passes.
Their employers have been summoned to the immigration office on Wednesday to assist with the investigations.