Four illegal migrant workers were arrested thanks to the keen eye of an off-duty police officer. The policeman was on his way to work when he noticed that some farmworkers in a cabbage field in western Taiwan were shying away from any vehicles passing by on the highway.

After observing the workers’ odd behavior, the policeman rushed to the office of Beigang Precinct of Yunlin County Police Department to report the discovery of suspected illegal migrant workers, The Commons Daily reported on Thursday.

Police conducted a surprise visit to the cabbage farm, chasing down the four suspects who were hiding in the field.

The four were later identified as Indonesians, two men and two women, who had illegally run away from their former employers because of low wages, and found work at the cabbage farm through compatriots’ referral.

The farm owner was also arrested for employing illegal migrant workers. He admitted to the police that he had hired the four suspects because of the keen demand for his vegetables and the huge size of the farmland, which required extra workers to help with the harvest.