The running time meant that the series overlapped with the beginning of rival ITV show Britain's Got Talent, where it should end at 8.30pm giving viewers enough time to switch channels.
Senior manager at ITV Mike Large tweeted: "Was The Voice tonight live? Surely that can be the only reason BBC1 overran by 3 minutes... those kind of overruns only normally tend to happen on live shows, don't they?"
As reported by The Mirror, a senior ITV source added: "This is out-and-out dirty tricks. The BBC always say they are above this kind of thing. Clearly they are not. They are outrageous."
ITV had moved Britain's Got Talent's start time to 8.30pm in order to avoid a clash with The Voice.
BBC sources dismissed the claims, saying: "Can they not see the irony that they manufactured this whole situation by bringing their show forward by four weeks and installing the half-hour overlap?
"The simple truth is the peak figures were not affected by the overlap and we won by a full one million viewers."
The weekend's Voice instalments were originally 100 minutes long, but were re-edited to 90 minutes in order to avoid an overlap.
A BBC source said: "The need to lose 10 minutes from each show explains why it overran slightly."
> 'Britain's Got Talent' pips 'The Voice' as ratings battle intensifies
> 'The Voice' UK reveals top 20 contestants as the battle rounds end
Photo gallery - The Voice UK Top 20: