The Tánaiste says fake ads using his image to promote cryptocurrency scams originated in Russia and Belarus.
Micheál Martin was speaking as he launched new defamation laws, which are partly designed to make it easier for people to identify the owners of accounts spreading false information about them online.
Last year, the Tánaiste brought High Court proceedings against Google for hosting the fake ads.
He says the company is working with him to identify those responsible - but says X has been much less co-operative:
"The fake ads seem to have originated from jurisdictions in Belarus and Russia. It seems that stolen credit cards were used to pay for the ads. Notwithstanding the fact that we've received the high court order. I've written again to Google to get further clarity on the steps it now intends to take".
