The House Intelligence Committee’s top Democrat, Rep. Adam B. Schiff, said Chairman Devin Nunes changed the FBI surveillance memo he sent to the White House after the committee had approved it.

The California Democrat tweeted late Wednesday that Nunes “made material changes to the memo he sent to White House.”

Schiff said his Republican counterpart’s changes were not approved by the committee when it voted to release the memo, which criticizes the FBI’s probe into President Donald Trump’s campaign.

“White House therefore reviewing a document the Committee has not approved for release,” he wrote.

BREAKING: Discovered late tonight that Chairman Nunes made material changes to the memo he sent to White House – changes not approved by the Committee. White House therefore reviewing a document the Committee has not approved for release. pic.twitter.com/llhQK9L7l6

— Adam Schiff (@RepAdamSchiff) February 1, 2018

Schiff attached a letter to Nunes to his tweet.

“Upon our discovery that the document sent for public review had been secretly altered, the Majority belatedly afforded the Minority an opportunity this evening to compare the document transmitted on Monday night by the Majority to the White House with the document made available to all House Members since January 18,” Schiff wrote. 

Schiff called the move “deeply troubling” since the White House is reviewing a document that was not cleared for release to the public.

“Because there were material changes made to the document unbeknownst to Committee Members and only revealed to us this evening, two days after the vote, there is no longer a valid basis for the White House to review this altered document,” Schiff wrote. 

Schiff concluded his letter by saying it was “imperative” that the document be withdrawn or that there be a new vote to release the document. 

But Republican committee member Rep. Brad Wenstrup characterized the changes that were made as minor ones.

“The only thing I was aware of were making some grammatical changes, and making sure that we did not describe someone’s job if it was a matter of national security, but the content wasn’t changed,” the Ohio Republican said.

Watch: Trump Touts Party Unity, Year One Accomplishments in Speech to GOP Retreat