United States President Donald Trump’s administration has refunded about $100bn in tariffs since the nation’s top court ruled against its use of emergency powers to impose duties on dozens of trade partners, according to customs officials.

The Trump administration collected about $166bn from US importers before the US Supreme Court struck down a large portion of the president’s tariff regime in a 6-3 ruling in February.

In a court filing on Tuesday, the US Customs and Border Protection (CBP) disclosed that it had returned more than three-quarters of $128.68bn in tariff revenues earmarked as “potential and certified refunds”.

“CBP’s financial accounting system receives updates from Treasury that indicate these CBP certified refunds are being regularly dispersed,” Brandon Lord, executive director of CBP’s Trade Policy and Programs directorate, said in the filing with the US Court of International Trade.

In its ruling, the US Supreme Court found that Trump exceeded his authority when he invoked the 1977 International Emergency Economic Powers Act (IEEPA) to impose fentanyl-related tariffs on Canada, Mexico and China, and broader “reciprocal” tariffs on more than 90 countries.

Trump angrily denounced the ruling at the time, branding the six justices who sided against him “fools” and “lapdogs” for the Democratic Party.

The ruling did not nullify Trump’s tariffs on specific industries invoked under the 1962 Trade Expansion Act, leaving intact duties on goods including steel, automobiles and copper.

Following the Supreme Court’s decision, the US Court of International Trade in March ruled that companies affected by the invalidated tariffs should be refunded.

Trump has continued to roll out new tariffs since the Supreme Court’s ruling.

Last month, his administration announced levies of 10-12.5 percent on imports from dozens of countries that officials claim have not taken sufficient action to combat forced labour.

On Monday, a group of 25 US states, including New York, California, Arizona and Colorado, filed a legal challenge against the latest tariffs, calling the measures a pretext to re-impose the duties struck down in February. (Al Jazeera)