The minister of foreign affairs in Papua New Guinea says there are estimated to be about 10,000 illegal workers in PNG.
Sir Rabbie Namliu made the statement as the government prepares to crackdown on illegal workers, with people in small shops and the forestry industry especially targeted.
Sir Rabbie says the high number of illegal residents is a result of corruption and incompetence in the system, and chronic underfunding.
He says he is considering making sweeping reforms to the visa system to deal with corruption, abuse and incompetence in the management of visas, and associated approvals for non-citizen workers and visitors.
Sir Rabbie says failures in the system were not only an embarrassment but a real threat to national security and social harmony.
He says the recent blanket ban on Chinese visa holders was the latest in a series of major blunders over the years.