Kaniva News reports Fijian and Chinese labourers are among the biggest offenders.
Now a Fijian community leader has asked for an amnesty and the Tongan government says it is considering changing the current policy for migrant workers and asking the Fijian authorities to make sure Fijian workers go home when their contracts expire.
The secretary of Tongaʻs Ministry of Foreign Affairs, Vaʻinga Tōnē, said there were 300 Fijian overstayers in Tonga.