One viewer wrote in to the Radio Times to complain that the Smeg fridge freezer company logo was seen on screen 37 times in one episode of the series.
Andrew Smith, from Manchester, also complained the firm's website said it had "once again teamed up with the show to supply six iconic ... fridge-freezers".
Executive producer Emma Willis said there was "absolutely no product placement in the series".
She said the BBC asked Smeg to remove the offending claim from its website which had gone up without its blessing.
A BBC spokesman said: "It is inevitable due to the nature of the show, the baker's activities and the set, that some equipment will be in shot but production are always looking to minimise product prominence where possible.
"A range of products from different suppliers are used on the show to ensure the bakers can fairly compete and meet their challenges. Love, the independent production company, had a loan agreement with Smeg to supply the fridges. That loan agreement did not meet editorial guidelines therefore it is being revised for this series.
"As part of a review we have found that a few of the supply arrangements need a clearer process. We are working with Love Productions to put in place additional measures to ensure that sourcing and supply of equipment is clear in relation to our guideline."