LONDON — Producers of the popular “Britain’s Got Talent” TV show and the dog trainer who won the competition are coming under fire after a “doggie double” was used to perform a trick.

Border collie Matisse was replaced by a lookalike dog for a tightrope-walking sequence during the routine in Sunday night’s live final.

Viewers of the program vote for the winner by calling in. They chose Jules O’Dwyer, a guide dog trainer, over a Welsh choir and a magician in the season-ending competition. Some said on Twitter they would have voted differently if they knew two dogs had been used.

Producers Tuesday apologized to viewers unaware that trainer O’Dwyer was using a team of dogs.

ITV chief Peter Fincham said that “in hindsight” it should have been made more clear to viewers that more than one dog was being used.

Broadcast regulator OFCOM said more than 200 complaints have been received. No decision has been made on whether a formal investigation will be launched.

O’Dwyer, who won 250,000 pounds ($383,000) for triumphing in the season finale, said she is shocked by the public’s reaction, which has included a number of Twitter complaints.

She said she used the second dog, Chase, because Matisse is uncomfortable with heights.