Immigration director-general Khairul Dzaimee Daud said the immigrants – comprising 32 men and 29 women, including 18 children and a six-month-old baby – were picked up in the operation which began at 11.30pm.

He said their surveillance found that the settlement had been in existence for the past six years, with 30 to 40 houses equipped with electricity and water supply.

“These immigrants are believed to have been using illegal power and water supply connections. The wastewater from toilets was pumped into the river.

“The condition of the settlement was very dirty and unfit for living. It also poses a health threat.

“Some of them grew chillies, yams and bananas and raised chickens to support themselves.

“Most of these foreigners worked as cleaners near this area,” he told reporters here.

Khairul said more than 30 immigrants were believed to have escaped.

The settlement had a surau, a grocery shop and a badminton court.