President Donald Trump’s claims that former President Barack Obama wire-tapped him is maintaining a dubious reputation.

After days of claiming Obama wire-tapped Trump’s final weeks of campaigning, GOP members are demanding answers, but not from Obama. Former Sen. John McCain (R-Arizona) said on Sunday that Trump needs to substantiate his claim or retract his statement about his campaign. Additionally, McCain said he suspects that Russia played a part in the election.

Thus far, Trump has not released any specific information regarding the alleged wire-tapping. One administration official said that Trump’s conclusion is based off a Breitbart article alleging Obama’s “silent coup.”

Because of this, during CNN’s “State of the Union” on March 12, McCain said he had “no reason to believe” President Trump’s claim.

“The President of the United States could clear this up in a minute,” he said. “All he has to do is pick up the phone, call the director of the CIA, director of national intelligence and say, ‘OK, what happened?”

The debates on the matter started on March 4 after Trump tweeted multiple messages that Obama wire-tapped the Trump Tower. Since then, McCain is just the voice of one more official demanding to know evidentiary support for the claim. Many national security officials say the statement is false, including former Director of National Intelligence James Clapper.

McCain said if Trump does not resolve his allegation, “it undermines the confidence the American people have in the entire way that the government does business.”

The truth about wire-tapping

Despite Trump’s argument, it is not a simple gesture for the U.S. President to wire-tap. According to the Foreign Intelligence Surveillance Act, law enforcement agencies, including the President, must get a warrant from a secret court to do so.

The act does allow warrants that focus on foreign communications, which may include U.S. correspondence. In President Trump’s case, it is possible this way the case, as numerous reports show Trump’s administration contacted Russian officials during the campaign. However, there is still no evidence suggesting Obama wire-tapped Trump Tower to investigate the Russian communications, which are a new development.

Russia’s campaign involvement

While officials have not proved Obama wire-tapping Trump Tower, McCain said his main concern is the administration’s ties to Russia.

“There’s a lot of aspects of this whole relationship with Russia and Vladimir Putin that requires further scrutiny,” he said. “So far, I don’t think the American people have gotten all the answers. In fact, I think there’s a lot more shoes to drop from this centipede.”

During President Trump’s campaign, officials say he and his administration frequently commented Putin and Russian officials. Investigators believe this communication played a part in Moscow’s hacking campaign that led to Hillary Clinton losing the election.

While Russia claims the U.S. is ‘demonizing’ the country over the false claims, reports show otherwise. Attorney General Jeff Sessions, for instance, forwent his position earlier this month after unsubstantiated defense against his involvement.

To combat the vast accusations, the House and Senate Intelligence committees are investigating Russian involvement in the election. Furthermore, they requested that officials include Trump’s wiretapping claims in the investigation.