I went to my local French tax office to ask where on the 2012 tax forms I should declare my 2011 Premium Bond winnings. After several phone calls by my advisor the head of the advisory section appeared and said quite adamantly that I do not declare them!
Recently I asked the UK NS&I about declaring UK Premium Bond winnings in France. I was told by my advisor - I waited while discussions were going on in the background between her and her technical advisor - that after June 2012 the NS&I will be reporting winnings to the HM Revenue & Customs which in turn will report them to the relevant French tax authority.
Any comment on the above please?

Yes, they should be declared in France. Local Tax offices are notorious for not understanding "unusual" tax situations.

And you pay CSG (social tax) on the total amount of winnings.

I was always under the impression that you couldn't hold Premium Bonds if you lived outside the UK!

Thank you Little Ann, I have looked further into this and I am satisfied that PB winnings are taxable, but what do I do now?

I could just do as they say - don't declare them - but I don't want to be penalised later on when they find out through their official channels that I should have declared them.
Do you know which box on the forms I should fill in, because I'm going back to see them to sort this out.

Hi,
Box 2TS on 2042 ; but why not put them in the name of a trusted UK resident family member?

or, why not, having asked the tax office & got a reply, believe them and ask them to put it in writing & sign it & have done with it. You have got a cast iron defence then if they ever query it in the future, which is probably unlikely.