In May the National Science Foundation suspended nearly $21 million in research grants to the University of California, Berkeley, after charging that principal investigators failed to disclose funding from outside the United States. The countries named in an April 13 letter from the agency to the university were the United Kingdom, Australia, and Switzerland — traditional U.S. allies that the federal government has not identified as security threats, according to the letter obtained by Berkeleyside and reported by the Associated Press.

Several of the lead researchers whose grants were suspended told Berkeleyside they had not received any funding from the countries the NSF specified. The Associated Press reported the researchers’ accounts in a story published Tuesday.

The April 13 letter from the NSF detailed the allegations of undisclosed foreign funding. The letter was obtained by the independent news outlet Berkeleyside, which shared its reporting with the Associated Press. The letter accused the principal investigators of failing to meet federal disclosure requirements for funding received from foreign entities.

MSI previously reported that researchers named in the suspension had denied receiving any foreign funding from the specified countries, as the Trump administration continued its broader campaign to tighten oversight over academic research. Read the prior article

The dispute could signal a new front in the conflict over research dollars between the University of California system and the Trump administration, the Associated Press reported. The White House has been waging a yearlong campaign to exert ideological control over college campuses and has proposed new rules giving political appointees more sway over federal grantmaking, according to the AP.

Dan Mogulof, a UC Berkeley spokesperson, declined to comment on the specific allegations when contacted by Berkeleyside, the AP reported. The university has previously challenged NSF funding suspensions in federal court.

The NSF suspension is the latest in a series of actions by the administration targeting research funding at universities, particularly in California. In May, the NSF suspended 18 grants to UC Berkeley despite a court order that had blocked similar actions, MSI has reported.

UC Berkeley has been a frequent target of the administration’s higher education policies. The university has faced multiple funding suspensions, leadership changes at federal science agencies, and new regulations that critics say give political appointees greater control over which research receives federal support.