The Catholic Church does not want people to donate "dirty money" earned by abusing low-paid workers, Pope Francis said on Wednesday.

"Some donors come to the Church offering profits from the blood of people who have been exploited, mistreated, enslaved with badly paid work," Francis said during his regular weekly audience with pilgrims at the Vatican.

"I will say to them: 'Please take your money away, burn it'," said Francis, who has made safeguarding the poor and cleaning up Vatican finances central tenets of his papacy.

"The people of God... do not need dirty money, they need hearts that are open to God's mercy," he said.

The pope has previously branded money "the dung of the devil" and condemned the evils of unbridled capitalism, prompting criticism from some US business leaders. He told a meeting of diplomats at the Vatican in 2013: "We have created new idols" and "the golden calf of old has found a new and heartless image in the cult of money and the dictatorship of an economy which is faceless and lacking any truly humane goal".

According to Pope Francis, a major reason behind the increase in social and economic woes worldwide "is in our relationship with money and our acceptance of its power over ourselves and our society".

Francis has increased the power of the Vatican's financial intelligence authority (AIF) but the European finance watchdog Moneyval said last year the Holy See still needed to be much more aggressive in prosecuting financial crimes.

The December 2015 report from Moneyval, the Council of Europe's lead agency in the struggle against corruption and the financing of terrorism, said that legal reforms in the Vatican had been positive. It said that the Vatican Bank had shut down nearly 5,000 suspicious accounts but that there had been "no real results" in terms of prosecutions for serious crimes or the confiscation of assets.

The evaluators concluded: "All in all, the basically sound legal structure that has been put in place... now needs to deliver some real results on the prosecutorial side in the Holy See and the Vatican City State."

Additional reporting by Reuters.