The Bundesbank, Germany's central bank, has the world's second largest stock of gold at 3,352 tonnes. One-third of it is stored at the Federal Reserve Bank of New York for reasons dating back to the Cold War and the monetary system created in the wake of World War Two.

Those holdings have occasionally attracted scrutiny in the past, and the right-wing Alternative for Germany (AfD) has embraced calls for a return of the country's gold back home.

US President Donald Trump's confrontations with longstanding allies over trade and security, and his attacks on the Fed, have revived the issue in recent weeks and more mainstream voices have joined the debate.

Germany's Taxpayers Federation sent letters this week to the Bundesbank and the Finance Ministry calling on them to repatriate the gold stored in the United States.

"Trump wants to control the Fed, which would also mean controlling the German gold reserves in the US" Michael Jaeger, the Taxpayers Federation's vice-president, told Reuters. "It's our money, it should be brought back."

Markus Ferber, an influential member of the European Parliament for Germany's ruling Christian Democrats, said the United States was "no longer the reliable partner it used to be."

"Trump is erratic and one cannot rule out that someday he will come up with creative ideas how to treat foreign gold reserves," he told Reuters. "The Bundesbank’s policy for gold reserves has to reflect the new geopolitical realities."

Public broadcasters ZDF and ARD have also recently carried reports asking how safe Germany's gold is in New York.

The Bundesbank said the New York Fed remained "an important storage location" for its gold.

"We have no doubt that in the New York Fed we have a trustworthy, reliable partner for the storage of our gold holdings," the central bank said in response to a Reuters enquiry.

The German Finance Ministry referred Reuters queries on the matter to the central bank, while stressing the Bundesbank's independence.

Any hint that Germany might be considering moving gold out of New York would be politically sensitive as it could be interpreted as lack of confidence in the Federal Reserve and its independence.

The European Central Bank last week stressed its trust in the Fed as a reliable partner. But Trump's frequent criticism of Fed chair Jerome Powell, whose term ends in a year, has fueled some concerns about the Fed's future independence and its long-standing commitments to its partners.

Peter Boehringer, the architect of the original decade-old gold campaign and now an AfD lawmaker, said he felt vindicated that the topic of repatriating gold reserves has now become a matter discussed by mainstream media and other lawmakers.

"When I started asking about the gold, I was dismissed as a conspiracy theorist," he said. "Today, after Trump, my concerns are shared widely."

Germany accumulated most of its gold during its 1950s-1960s export boom. A key advantage of storing some of it in New York during the Cold War was to keep it at a safe distance from Russia in case of an invasion.

The gold also cemented a military alliance with the United States, which still has dozens of military bases around Germany, including Europe's largest.

With the Soviet Union long gone, the Bundesbank brought back 300 tonnes of gold from New York between 2014 and 2017, saying it wanted to "build confidence at home".

But Russia's invasion of Ukraine, and the implicit threat it represents for the rest of Europe, was likely to complicate Germany's geopolitical calculus again.

For Ferber, this underscored the need for greater diversification across several, and potentially new, locations. Today, Germany's gold reserves are held at the Bundesbank headquarters in Frankfurt, in New York, and at the Bank of England in London.

"For gold reserves, diversification is key. Having all eggs in too few baskets is never advisable," Ferber said, without specifying where the gold should be brought.

Fritz Guentzler, a spokesperson for the Christian Democrats in the German parliament, said he had no reason to mistrust the Fed but the Bundesbank should continue "regularly inspecting the stocks" of gold.

The Bundesbank said it ran regular sample tests and had inspected 13 percent of stock in New York over the years.