Marine police on Monday said, they had detained 22 Indonesians, including nine women, who were being smuggled back to Indonesia after working illegally in Malaysia.
Southern Johor state marine police chief Mohammad Khamsani Abdul Rahman said, a patrol spotted two speedboats late Saturday night off the southern coast and captured the group after a high-speed chase.
"We have detained the 22 for investigations and initial reports show they were working here illegally and were being smuggled back to Indonesia when we caught them", he told AFP.
He said the boat's captain was being questioned as investigators looked at the possibility he was part of a human trafficking syndicate.
"We are seeing increasing cases of such groups trying to sneak in and out of the country as the government has been reducing the number of foreign workers here", he added.
Khamsani said 106 illegal immigrants have been detained off Malaysia's southern waters since January this year. A total of 564 were held in 2009.
Malaysia has announced plans to reduce the 1.9 million foreign workers in the country while unveiling last week a national plan to combat human trafficking.
Last July, Malaysian police arrested five immigration officials for involvement in an international syndicate that smuggled refugees from Myanmar's Rohingya Muslim minority into the country.
Malaysia has one of Asia's largest populations of foreign labourers, who it relies on to work as domestic servants and in plantations and factories.