Ghana deported 4,700 illegal miners last year, most of them Chinese nationals, deputy information minister Ibrahim Murtala Muhammed said on Thursday.

"Most of them were Chinese illegal miners. Largely, they were arrested by the special task force," Muhammed said, adding that Nigerians, Russians and South Africans were also expelled.

Local police and a task force of military, police and immigration officials began targeting illegal miners last year on the orders of President John Dramani Mahama.

Chinese foreign minister Wang Yi visited Ghana last month on a four-nation African tour and pledged Beijing's support to help tackle the issue.

Small-scale mining is legal in Ghana but it is illegal for foreigners and local communities have complained that the mines damage the ecosystem and pollute waterways.

High gold prices over the last few years have attracted thousands of foreigners to Ghana's gold-producing middle belt, where they collaborate with Ghanaians to mine small-scale plots.

While gold prices have waned in recent months, foreign investors have been attracted to Ghana by the country's stable democratic government and resurgent economy.

Ghana, west Africa's second largest economy, is also a major exporter of cocoa and started producing oil in 2010.