The European Central Bank could buy loans and other assets from banks to help support the eurozone economy, Germany's Bundesbank has said, marking a radical softening of its stance on the contested policy.

Jens Weidmann, who is a member of the European Central Bank's Governing Council, told MNI in an interview published on Tuesday that the ECB could consider purchasing eurozone government bonds or top-rated private sector assets.

"Of course, any private or public assets that we might buy would have to meet certain quality standards," Weidmann said.

"But the overall question is one of effectiveness, costs and side-effects. We are currently discussing the effectiveness of these measures. The intended effects would then have to be weighed against the costs and side-effects."

With little room for the ECB to cut interest rates further from a record low 0.25 percent, Weidmann called in the interview, which MNI said was conducted on Friday, for a debate about the effectiveness of other policy tools.

"The unconventional measures under consideration are largely uncharted territory. This means that we need a discussion about their effectiveness and also about their costs and side-effects," he said.

The Bundesbank represents the 18-member eurozone's biggest economy, Germany, and its president's words carry weight in the debate over what the ECB should do as traditional tools such as changing borrowing costs lose their force.

He cited limits under the ECB's mandate on funding eurozone governments, which a pending German constitutional court ruling on the legality of its Outright Monetary Transactions bond purchase program is expected to underline.

"This does not mean that a QE program is generally out of the question. But we have to ensure that the prohibition of monetary financing is respected," Weidmann said.

"We need to discuss this and ideally achieve a common view."

Quantitative easing, or QE, is when a central bank buys loans or other assets from banks. It would represent a radical departure for the ECB.