Congressman Adam Schiff claimed on Sunday that the official who sits atop the intelligence community is rejecting a subpoena to turn over a whistleblower complaint in order to protect an even higher-ranking official, possibly a top administration official or even President Trump.

"According to the director of national intelligence (DNI), the reason he's not acting to provide it, even though the statute mandates that he do so, is because he is being instructed not to. This involved a higher authority, someone above the DNI," Schiff, who is chairman of the House Intelligence Committee, said in an interview with CBS News' "Face the Nation."

Schiff had issued a subpoena Friday to Joseph Maguire, the acting DNI, alleging that he was unlawfully withholding the whistleblower complaint from the committee. A letter sent with the subpoena said that Maguire's office had "improperly" cited the complaint's "confidential and potentially privileged communications" as its reason for withholding it.

"The Committee can only conclude, based on this remarkable confluence of factors, that the serious misconduct at issue involves the President of the United States and/or other senior White House or Administration officials," Schiff wrote in the letter. While he said he couldn't divulge the contents of the complaint, the fact that the DNI had cited "privileged communications" means that it would involve a "pretty narrow group of people."

"So, I think it's fair to assume this involves either the president or people around him or both," Schiff said.

Further, the complaint had been deemed "credible" by the inspector general of the intelligence community (IC IG). By Friday, more than 10 days had lapsed since Maguire was supposed to hand over the complaint.

"At the end of the day, if the director of national intelligence is going to undermine the whistleblower protections," Schiff said. "It means that people are going to end up taking the law into their own hands and going directly to the press, instead of the mechanism that Congress set to protect classified information."

That, he said would threaten U.S. national security and the whistleblower system "that encourages people to expose wrongdoing."

"No DNI — no director of national intelligence — has ever refused to turn over a whistleblower complaint," Schiff added.

The IG, he pointed out, "did some preliminary investigation, found the whistleblower to be credible, that suggests corroboration. And that it involved serious or flagrant wrongdoing."

Schiff said he is concerned that the complaint "involves wrongdoing that's under investigation by our committee." He added that the committee would do "everything necessary" to ensure that the whistleblowers who were not allowed to give their complaint to the committee "can come directly to Congress." However, according to Schiff, the director is "also prohibiting" this, too.

Schiff said in a statement that more than 10 days had lapsed since Maguire was obligated to hand over the complaint, which had been deemed "credible" by the inspector general of the intelligence community.

Mr. Trump named Maguire, a retired vice admiral who was serving as director of the National Counterterrorism Center, acting DNI last month after former DNI Dan Coats and Principal Deputy DNI Sue Gordon offered their resignations.

Gordon, a career official who would by law have assumed the acting role, included a note alongside her resignation letter indicating she was not leaving by choice. "You should have your team," she wrote to the president.

Reporting by Olivia Gazis.