Chad on Monday said it had lifted an expulsion order against an Italian Catholic bishop who had been ordered to leave after criticising the mismanagement of oil revenues in the impoverished central African country.

"The government... announces that the measure expelling Monsignor Michele Russo... from Chad is lifted," Communication Minister Hassan Sylla Bakari said on national radio.

The minister said that Russo could return to his post in the oil-rich southern region of Doba as soon as the official order lifting the expulsion is published.

He did not provide further details.

Chad in October announced the expulsion of Russo, who had been bishop in Doba for 23 years and who had campaigned for ordinary people to receive a much greater share of Chad's new oil wealth.

Russo, who had done 36 years of missionary work in Chad in all, returned to Rome on October 14 following the expulsion.

Chad authorities said a sermon delivered by the 67-year-old Russo and broadcast by a private radio station was "likely to disturb public order" and that the bishop had "engaged in activities incompatible with his status".

Russo's small diocese has 10 parishes and some 400,000 inhabitants, of whom around 20 percent are Catholic. A majority of Chadians are Muslim.

Russo has long been critical of the government of the country that began producing oil in 2003 and in a statement to the Vatican missionary news agency Fides in early October he said Africa's natural wealth had been mismanaged for decades by "human greed" and had turned "into a curse for the local population."

"After 50 years of uncontrolled exploitation, with the complicity of local governments and indifference towards the African people and their future, I think it's time to become aware of these facts," he added.

Chad produces on average around 120,000 barrels per day, according to government estimates from 2011.

Oil revenue has allowed the poverty-stricken central African country to modernise its army, upgrade its roads and build numerous public buildings.

But there has been criticism of the government in some quarters for not doing enough with the windfall to better the lives of ordinary Chadians.