A total of 4,815 complaints regarding the wages of migrant workers were referred to public security organs for further investigation in 2015, according to the Ministry of Human Resources and Social Security.

Most concerned the nonpayment of wages and enforced pay cuts.

However, the problem of wage defaults "has been contained" since refusing to pay employees was made a crime under a 2011 amendment to the Criminal Law, ministry spokesman Li Zhong said during a news conference on Friday.