Senior White House adviser Kellyanne Conway is suggesting that alleged government surveillance of Donald Trump during his campaign may have gone beyond the president's accusation that former President Barack Obama had his phones tapped.

Conway tells New Jersey's Bergen County Record “there are many ways to surveil each other.” She says “you can surveil someone through their phones, certainly through their television sets any number of ways.” Conway did not offer any evidence for the remark.

It follows Trump's claim that Obama had Trump's “wires tapped” at Trump Tower before the election. Trump hasn't provided evidence and Obama has denied the charge.

FBI director James Comey has privately urged the Justice Department to dispute Trump's claim but has not come forward to do so himself.

A senior congressional aide said on Saturday that the House intelligence committee asked the Trump administration to provide by Monday evidence that the phone were tapped, a request reinforced Sunday by an influential Republican, Sen. John McCain.

“I think the president has one of two choices: either retract or to provide the information that the American people deserve, because, if his predecessor violated the law, President Obama violated the law, we have got a serious issue here, to say the least,” the Arizona senator said.

Trump asserted in a tweet last week: “Terrible! Just found out that Obama had my 'wires tapped' in Trump Tower just before the victory. Nothing found. This is McCarthyism!” He continued the allegation against former Obama in other tweets but offered no evidence.

The request for evidence by Monday was made in a letter sent to the Justice Department by the House committee chairman, Rep. Devin Nunes, R-Calif., and the panel's ranking Democrat, Rep. Adam Schiff, D-Calif., said the congressional official. The aide wasn't authorized to discuss the request by name and requested anonymity.

Obama's director of national intelligence, James Clapper, has said that nothing matching Trump's claims had taken place, but that has not quelled speculation that Trump's communications were monitored by the Obama administration. Trump has asked Congress to investigate.