The BBC has come under criticism for The Voice UK, with some complaining that the show is just an advertisement for Universal Music.
But three of the show's coaches are also signed to the label, and have seen huge increases in sales thanks to numerous plugs to the programme's 10 million viewers.
Amazon report that Jessie J, Sir Tom, The Script and The Black Eyed Peas are all enjoying big lifts in the number of albums they're shifting since the show started last month.
One MP, Philip Davies, complained: “The BBC has paid a fortune for The Voice.
“This now looks to be a very expensive advert for the record company, which not only gets a heavily-promoted winner but also a boost for its existing artists.”
He added: “The BBC appears to be using this format as a spoiler to sabotage ITV’s success with Britain’s Got Talent. I don’t think this is what the BBC should be doing.”
A BBC spokesman hit back: “The Voice is an established global format with pre-existing arrangements.
“The BBC have taken appropriate steps with Wall To Wall to ensure these are acceptable.
“In casting the coaches we spoke to the biggest stars in the music industry regardless of the labels they were attached to.
“Two of three major labels are represented on the panel and throughout the series other labels will continue to be represented.”