A Conservative MP who claimed the Guardian had endangered national security with its reporting of top secret intelligence files has a picture on his official website of him posing with staff from the high-security US base in North Yorkshire, Menwith Hill.

Julian Smith, MP for Skipton and Ripon, raised concerns about the Guardian's coverage of the US National Security Agency files, leaked by whistleblower Edward Snowden, in a House of Commons debate on Tuesday. He wrongly claimed it had distributed information about British intelligence agents and called for the Guardian to be prosecuted.

"To communicate, not just publish, any identifying information about GCHQ personnel is a terrorist offence," he told MPs.

However, on his website, he has publicly identified staff from the high-security US base, publishing a picture of himself posing with more than 30 people outside the House of Commons. The caption reads: "Julian has welcomed a group of around 40 people from RAF Menwith Hill to Westminster." The picture is also on Smith's Facebook page where it states: "Enjoyed meeting members of the British-American group from RAF Menwith Hill".

The Guardian has republished the picture, pixelating the faces of everyone except the MP to ensure there is no threat to national security.

Smith said on Friday: "The people that came on that trip would have given me full permission to use any photograph."

The base is the NSA's key eavesdropping hub in Europe and has an array of radomes, commonly called "golf balls", which are used for satellite communications interceptions. Although the base is called RAF Menwith Hill, most of the staff there are US employees of the NSA.

On a visit to the site in June 2008, the head of the NSA, Lieutenant General Keith Alexander set staff an ambitious task. "Why can't we collect all the signals all the time?" he asked. "Sounds like a good summer project for Menwith."

According to the files released by Snowden, Menwith Hill was also the listening station that intercepted the telephone calls of the then Russian president Dmitry Medvedev when he was in London for the G20 summit in 2009.

Smith, who has made a complaint about the Guardian to the police, called this week's debate in Westminster Hall to raise his concern at how the Guardian handled the Snowden files, claiming the paper had endangered the lives of intelligence agents. The backbencher's address was condemned as McCarthyism and "absolute scaremongering" by Labour MPs who were prevented from speaking.

Smith said: "The Guardian focused on sending abroad revelations not about the American NSA or whistleblowing. They chose to distribute information about our own intelligence agents and GCHQ … to communicate, not just publish, any identifying information about GCHQ personnel is a terrorist offence. This is not press freedom – this is the Guardian's devastating impact on national security."

A spokeswoman for Guardian News & Media said Smith's speech "propagated a series of myths" about the Guardian's reporting of the Snowden documents. "When responsible journalists working on the same story share documents they are engaged in journalism not terrorism. Senior politicians and government officials in the UK and internationally, over 30 of the world's leading newspaper editors, and an overwhelming majority of the public, have all said that the Guardian's reporting on this story is important for democracy."

She added: "They all agree, as does Mr Smith, that surveillance of citizens by intelligence agencies is a legitimate subject for debate. But there would be no public debate had there been no disclosure."