Donald Trump Jr. on Wednesday accused his father’s former White House staff of being part of a smear campaign against him.

In a letter to congressional investigators, the Republican presidential nominee and former White President’s eldest son accused the FBI and other law enforcement agencies of conducting an “unprecedented smear campaign” against him and his family and accused them of attempting to derail his candidacy for president by using the “failing” media to do so.

“This smear campaign is being run by the same political operatives who have attacked my father for so many years, and they are using the same discredited ‘birther’ conspiracy theories as part of their disinformation campaign,” the letter said.

“In fact, some of the people who have used the same conspiracy theories are working for your father’s political opposition, including the infamous James Comey, who has made numerous false claims about my father’s administration.”

Trump Jr. wrote that the FBI had sent him a letter in January 2016 that contained a series of allegations that included “a report that my father ordered his campaign staff to compile a dossier on me, and that I had participated in a conspiracy to obstruct justice.”

The letter did not provide a timeline for when the bureau allegedly received the allegations and whether it was related to Trump Jr.’s meeting with a Russian lawyer during the 2016 presidential campaign.

The letter was dated March 4, 2017, but was signed by Trump Jr., Jared Kushner and Paul Manafort, who are all senior advisers to Trump.

The letter also accused the federal investigators of using “unverified, damaging allegations” against Trump Jr in a statement released by his lawyer on Wednesday, after the House Judiciary Committee announced that it was conducting an investigation into the meeting.

The House Judiciary panel on Wednesday announced that the panel would be investigating allegations of Russian interference in the 2016 U.S. presidential election, a move that will likely be met with resistance from Democrats and some Republicans.

Trump Jr.’e lawyer did not immediately respond to a request for comment.

The White House, which was quick to respond to Trump’s letter, said the allegations contained in the letter “do not reflect the views of the President.”

In a statement, the president’s son said he was “deeply concerned” by the accusations, adding that he had “no idea” what “unsubstantiated and false claims” they contained.

“I am disappointed that the committee is considering any and all allegations that I participated in this sham campaign of Russian lies,” Trump Jr wrote.

“I am confident that the truth will set them straight.”