AGRICULTURE Minister Barnaby Joyce has been busted for a third time using taxpayer funds to attend a wedding.

Mr Joyce last night said he would repay more than $300 he wrongly claimed on ComCars after The Daily Telegraph discovered he made four trips to attend a journalist friend's Brisbane wedding five years ago.

The latest incident comes after Mr Joyce repaid more than $600 for wrongly charging taxpayers for the 2011 wedding of Sydney radio shock jock Michael Smith.

He is still investigating another wedding road trip after admitting in September he "probably" used his fuel card to detour more than 100km to host the 2010 Gold Coast nuptials of then Queensland LNP colleague Hajnal Ban.

Mr Joyce said: "The association with the groom came as a result of my role as a politician.

"I attended as a guest and I spoke at the wedding.

"Nevertheless, given the recent uncertainty about claims of this nature, I will pay back the ComCar claims."

BARNABY JOYCE CHECKING WEDDING RECORDS