Some of the undisclosed payments to Mr Tubridy from RTÉ were made through a UK-based "barter account" operated by the organisation, but there is confusion over how exactly that was done.

Media companies often use these to trade advertising space in return for goods and services instead of cash.

Mr Kelly told politicians on the media committee he had no knowledge of the barter account system and thought the payments to Mr Tubridy had come from Renault.

"We trusted the process, why would we not trust the process?," he said.

He rejected any suggestion he colluded with the broadcaster to conceal the true nature of the payments.

Mr Tubridy also said he had not tried to conceal any "secret agreement" with Renault.

"I signed a contract in good faith, I declared my earnings, I paid every cent of tax," he said.

"My employer has acknowledged that, it has engaged in deceptive practices to pay me, practices that were hidden from me.

"The result of this is that I've become the face of a national scandal, I've been accused of being complicit, deceitful and dishonest."

He said, though, he took "full responsibility" for not asking more questions about how his pay was declared by the broadcaster.

Mr Tubridy added later in the day that he would return €150,000 to RTÉ if corporate events for Renault he was paid in advance to host do not take place.

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