VATICAN CITY — The head of the scandal-marred Institute for the Works of Religion, better known as the “Vatican bank,” declared Thursday it’s now “impossible to launder money” there after a years-long cleanup that saw norms imposed to fight money laundering and tax evasion.

Jean-Baptiste Douville de Franssu made the claim as the bank reported net profit of 16.1 million euros ($18.3 million) last year, down from 69.3 million euros in 2014. The bank attributed the decrease to lower interest rates and market uncertainties and provisions to fix a foreign tax issue.

In an interview with Vatican media, de Franssu acknowledged that in the past the IOR had been subject to abuse “because you cannot serve two masters, and money is tempting.”

But now that new norms are in place, he said: “It is impossible to launder money at IOR.”

The bank has some 14,801 customers. About half are religious orders which use its investment services and to transfer money to missions around the world. Other customers include Vatican offices and employees. Total client assets under management at the end of 2015 were 5.8 billion euros ($6.6 billion).

Each year, the bank gives the pope around 50 million euros, much of it to run the Holy See. This year, Pope Francis is only getting the 16.1 million euro profit.

The bank’s general director, Gian Franco Mammi, suggested that in previous years, the bank had dipped into its capital to make the donation.

“The novelty this year — and for me it is a great pleasure to be able to communicate this — is that the contribution has come only from the actual profits and not the capital,” he told Vatican newspaper and radio.

For fiscal year 2014, the IOR gave the pope 55 million euros from a profit of 69.3 million euros. But in fiscal year 2013, the IOR gave him 54 million euro even though it only turned a 2.9 million euro profit, suggesting that the majority of the donation came from capital that was needed to run the Holy See.

The IOR embarked on a lengthy and costly cleanup to ascertain who exactly held accounts there and whether they were entitled to after years of scandals.