Aidan Burley, who was sacked from his junior government role last year after attending a Nazi-themed stag party, has become embroiled in a row over his "conduct" while listening to a Holocaust survivor.
Mr Burley, the MP for Cannock Chase, was part of a two day private visit to Auschwitz and other sites in Krakow with Dr James Smith, founder of the Beth Shalom Holocaust Centre in Nottinghamshire.
An onlooker has accused Mr Burley of "texting and dozing" during the concentration camp survivor's talk.
Matthew Perkins, a student on a history trip that Mr Burley joined for the talk, said: "He was in the speech with us and he was blatantly disrespectful throughout
The allegation, first made on Twitter, was then raised in a commons Business Questions session by Ian Austin, Labour MP for Dudley, who said it was time "the government sorted this whole affair out by publishing the outcome of the inquiry and organising a debate on the investigation."
But according to a friend in the Conservative Party, Mr Burley "did not doze off once" but behaved "completely respectfully and found the visit moving".
The friend admitted that Mr Burley may have "briefly answered an urgent message from London". He said it was not surprising that Mr Burley had left his phone on "because you never know what you might have respond to."
The friend also claimed that other participants were "aggressive" toward Mr Burley during the trip. "When they arrived at Auschwitz there was an English group there and one person realised who Mr Burley was. They behaved quite aggressively before the lecture. The impression was that they were looking for trouble."
He said it was sad that people were "trying to make political capital out of what was a very solemn and moving two days for Aidan."
Sir George Young said it Mr Burley's actions were not a matter for the government to look into but should be handled by the Conservative party.
Mr Austin, whose adoptive father escaped to Britain from Czechoslovakia on the eve of the Holocaust, said: "The students have suggested that he did not take the lecture as seriously as he should have."
The 32 year old, who was elected at the last general election, was filmed at an event in the ski resort of Val Thorens where one guest donned an SS uniform and others allegedly toasted the Third Reich and chanted the names of senior Nazis.
The Prime Minister sacked him as Parliamentary Private Secretary to Transport Secretary Justine Greening and asked for a fuller investigation of the matter.
French police have opened an enquiry into the event, on the grounds that it is a criminal offence in France to wear or exhibit Nazi uniforms and insignia.
Mr Burley has not yet responded to a request to comment.
Dr Smith said that Mr Burley's actions were being blown out proportion and called for "perspective".
"I was sitting next to him and though I was concentrating on the survivor's talk, not Aidan, if he were asleep as has been said, I am sure I would have noticed," he said.
He emphasised that the trip was paid for by Mr Burley and was not intended as "a media gimmick, but rather it was to be a meaningful learning experience".
"This was not an isolated trip. Aidan planned to visit The Holocaust Centre to meet with survivors and observe educational programmes about the Holocaust," he added.
"I don't minimize the stag night whatsoever and take the Holocaust extremely seriously."