He noted that the surveillance was not related to Russia or the investigation of Russian activities, or of the Trump team.
"I think the President is concerned and he should be," Nunes added. The committee still needs more time to investigate, but some of the espionage activity "seems to be inappropriate."
He also said that the committee would launch a probe to investigate who was aware of the "incidental" wiretapping and who ordered to keep the information secret.
Commenting on Nunes’ statements, Trump noted that he felt "somewhat vindicated" on his claims against Obama.
"I must tell you, I somewhat do. I very much appreciated the fact they found what they found," Trump said at the White House.
The fact that Nunes first spoke to journalists and then reported at the White House outrages Democrats and members of the intelligence community.
For example, Adam Schiff, the ranking Democrat on the Committee, said that first of all Nunes should have briefed him. He also expressed confidence that Nunes’ actions may challenge the credibility of the investigation as well as the probe into Trump’s team alleged connections with Russia.
"The chairman will need to decide whether he is the chairman of an independent investigation into conduct which includes allegations of potential coordination between the Trump campaign and the Russians, or he is going to act as a surrogate of the White House because he cannot do both," Schiff said.
"What if it’s one of the president’s people who is being investigated. Is he going to damage the investigation? It all feels very, very odd," Himes said.
Eric Swalwell, another member of the intelligence panel, also expressed concerns over the situation.
"The House Intelligence Committee is charged with investigating Russia's interference into our election and whether any U.S. persons were involved.
The chairman's actions and closeness to a president whose campaign is under federal investigation have gravely damaged the Investigation's credibility," Himes said in a statement cited by Politico.
Nevertheless, Nunes did not officially confirm Trump’s accusations against Obama. Initially, Trump insisted that it was Obama who ordered the wiretapping at Trump Tower during the electoral campaign, in October 2016.
Testifying before the House Intelligence Committee, James Comey, director of the Federal Bureau of Investigation (FBI) also rejected Trump’s claims against Obama, saying there was no evidence.
Never miss a story again — sign up to our Telegram channel and we'll keep you up to speed!