The top Republican and Democrat on the House Intelligence Committee opened Monday's hearing on Russian election meddling by immediately disavowing President Trump's claim that he was wiretapped by President Obama. 

“I’ve been saying this for several weeks, we know there was not a physical wiretap of Trump Tower,” chair Devin Nunes (R-Calif.) said during a brief opening statement. “However, it is still possible that other surveillance activities were used against President Trump and his associates.” 

Ranking member Rep. Adam SchiffAdam Bennett SchiffTop Russia probe Republican: 'No intention' of calling Cambridge Analytica officials back Overnight Tech: Facebook faces crisis over Cambridge Analytica data | Lawmakers demand answers | What to watch for next | Day one of AT&T's merger trial | Self-driving Uber car kills pedestrian Overnight Cybersecurity: Trump-linked data firm Cambridge Analytica attracts scrutiny | House passes cyber response team bill | What to know about Russian cyberattacks on energy grid MORE (D-Calif.) — in a lengthy opening statement — said that the committee has found "no evidence whatsoever to support that slanderous accusation."

The intelligence panel leaders made the statements during the committee's first open hearing on Russia's election interference.

Both Nunes and Schiff have previously said there is no evidence of Trump's claim that Obama had his "wires tapped" in Trump Tower ahead of the presidential election, a charge he made on Twitter earlier in March. Trump has stood by his claims, though the White House has worked to walk back the accusation, saying it referred more broadly to surveillance activities by the Obama administration. 

The Justice Department last week sent documents to the committee related to Trump's claims. 

Committee members will question FBI Director James Comey and NSA Director Adm. Mike Rogers Monday on the investigation into Russian interference in the election.