The BBC has secretly edited the audio recording of its Question Time election special last week after viewers complained that a whispered voice said "I hate him" as Rishi Sunak walked out to take audience questions.
The unedited online version of the Question time programme - which saw the four main party leaders - was available on the BBC's website last Friday.
The comment was made as the Prime Minister walked out to be greeted by presenter Fiona Bruce. After greeting Bruce, who said "Nice to see you", the whispered remark could be heard.
Some said they heard "I f***ing hate him" or *I hate him". There was speculation online that the remark could have been uttered by a BBC staff member who was near to one of the studio microphones.
The BBC was accused of editing the clip of Rishi Sunak on Question Time
PA/BBC
After the online speculation, the corporation then edited the programme so the whispered remark was removed from the audio after the speculation emerged online.
The BBC declined to comment but a corporation source told GB News that it had looked into the matter and the enhanced audio found the remark was "OK", which it attributed to Sunak himself.
The source said: "No one is saying 'f***ing hate him."
Asked why the original recording was not restored after the investigation the source said: "We left the edit - there was no reason to put it back in."
The explanation was given short shrift by the Conservative party. A Tory source said it was "a ridiculous excuse".
He added: "The remarks are clearly not 'OK' in content or in principle.
"Instead of quietly trying to edit things out and hope nobody notices they should come clean, find out who said what we can all clearly here and take action if they are a BBC employee."
The BBC is hosting a head-to-head TV debate between Sunak and leader of the Labour Party Sir Keir Starmer tomorrow, Wednesday 26 June.
Hosted by presenter Mishal Husain, the BBC Prime Ministerial Debate will be broadcast from Nottingham at 8.15pm on BBC1.
Following the debate, Laura Kuenssberg and Clive Myrie, the hosts of the BBC's election night coverage, will present reaction and analysis live from the debate venue.