Possible cheating in Art GCSE - should I tell someone?

[Perturbed]

Name changed for this. I have a DC who goes to a local comp and is currently in year 8. DCs BF has a sibling in year 11 who is doing Art GCSE. DC and BF were at BF's house, discussing how much they dislike a certain art teacher. BF's sibling and mum who were in the room, piped up and said how helpful art teacher had been as s/he had literally completed some of the art coursework for sibling and told sibling not to worry about the unseen exam as s/he would help with that as well! This made me quite annoyed not least because I have another DC doing Art GCSE at another school who has spent hours and hours of their own time doing it all alone. My own DC is good at art and would like to do GCSE when the time comes but I would be mortified if DC was "helped" by the teacher - should I say something to the school or exam board? I don't want to land the BF's sibling in trouble but I am absolutely furious and quite disturbed by this and wonder if it extends further than the art department.

Thank you all for your comments and I am sorry to have upset all you art teachers! Of course I don't want to land this child in it or accuse an innocent teacher. Teacher does have a history of making alterations to work for exhibitions and competitions so it does ring true I'm afraid. Presumably if cheating goes on someone will eventually become aware and it is not my responsibility. I hope my DC doesn't get this teacher for GCSE and I am glad my other child will do well on their own initiative.

Pmsl

I think you should concentrate in your own "DC" and your own life, you are sending around a feeling of lack of confidence and envies. Nobody should have time to be worried about what others do. There is not sense in what you write here.

You will probably disrupt the life of a kid and a teacher just because the gossip of your own kid. Why instead don't you teach your kid to use his time doing something constructive? instead of talking of bc's mothers, and teachers and supporting his feelings of envies?.
You should be teaching your DC to be the greatest he can be, not to grow up paying attention to what others do wrong. 8 years old?, what are you teaching him?

Year 8 Leslie, not 8 years old.

That said, I think OP should lay off. Hearsay only, she might well have got the wrong end of the stick and if what she's most worried about is her DC having help which she feels would compromise his or her artistic integrity - well, in three years time the teacher might have either changed tack or moved on.

Of course there can be cheating teachers, just like there can be murderous doctors and shagging monks; the fact that something is forbidden and dangerous to your career does not prove that it never happens.

But your problem is that you have no evidence that it happened in this case, having only hearsay to go by. The only person who could (and should) make a complaint is the student whose work got altered: if she is not prepared to do so, then there is nothing to be done.