The Coronation Street actress, who plays Stella Price, has been criticised by some sections of the press for her Northern accent.
Collins interrupted Walsh's special comedy turn by bellowing, "Boring now!", according to The Sun.
"Bradley did a routine where he turned the camera on to various stars and guessed what they were thinking," an insider explained.
"For Michelle, it was something along the lines of 'I wonder if there's an award for an accent?'
"Then he made a jibe about Emmerdale's Paddy wishing he was at a Greggs bakers and one about Corrie's Antony Cotton and kangaroo anuses from I'm a Celeb."
The source went on: "Michelle was not happy and shouted at him: 'Boring now!'"
However, the pair apparently "made up" afterwards, and Walsh - previously a cast member on Corrie - "blamed scriptwriters".
An informant added: "But it really chilled the atmosphere and was pretty embarrassing all round.
"The show's producers promised they would cut it from the final edit for Wednesday night's broadcast. But it remains to be seen whether or not it will stay in."
The British Soap Awards will be screened tomorrow night (Wednesday) from 8pm on ITV1.
> British Soap Awards 2012 - winners in full
> British Soap Awards 2012 afterparty - pictures
> British Soap Awards 2012 - red carpet arrivals in pictures
Photo gallery - British Soap Awards 2012 winners: