The U.S. House Judiciary Committee sent a subpoena to Harvard University on Thursday seeking documents and communications for its probe into tuition costs and financial aid for Ivy League students.

A letter to Harvard President Alan Garber, signed by committee chairman Jim Jordan and U.S. Representative Scott Fitzgerald, both Republicans, described Harvard's response to previous requests for documents as inadequate and said the committee needs the documents "to fulfil its oversight and legislative responsibilities."

A spokesperson for Harvard said in a statement: "We are disappointed that the Committee has chosen to issue a subpoena and believe it is unwarranted, unfair and unnecessary."

It added: "There is no basis for an allegation of collusion in Harvard’s setting of tuition and financial aid."

The investigation into tuition is part of a larger fight between Harvard and the White House and Congress, including over cuts to federal funding and efforts to block foreign students from attending the university.

President Donald Trump has said he is trying to force change at Harvard - and other top-level universities across the U.S. - because in his view they have been captured by leftist "woke" thought and become bastions of antisemitism.

The subpoena comes as part of an investigation by the Republican-controlled U.S. House Judiciary Committee into whether Harvard and other Ivy League schools broke antitrust laws by raising tuition costs.

"We are concerned that Ivy League member institutions appear to be collectively raising tuition prices while engaging in perfect price discrimination by offering selective financial aid packages to maximize profits," the letter to Harvard's Garber said.

U.S. Representative Jamie Raskin, a Democratic member of the Judiciary Committee, called the investigation "plainly ridiculous" and "based on pathetically weak allegations."

The Harvard spokesperson said the school has produced thousands of pages of documents on its tuition-setting process and financial aid.

While the Judiciary Committee said it had received hundreds of requested documents, it added that some of them contained publicly available facts and lacked specific information that was desired.