In a statement released on Twitter, Carr told his followers that he had made an "error of judgement", and that he is no longer part of the practice.
He wrote: "I appreciate as a comedian, people will expect me to 'make light' of this situation, but I'm not going to in this statement as this is obviously a serious matter.
"I met with a financial advisor and he said to me, 'Do you want to pay less tax? It's totally legal.' I said 'Yes.'
"I now realise I've made a terrible error of judgement."
He added: "Although I've been advised the K2 Tax scheme is entirely legal, and has been fully disclosed to HMRC [Her Majesty's Revenue and Customs], I'm no longer involved in it and will in future conduct my financial affairs much more responsibly. Apologies to everyone."