Joe Duffy temporarily signed off from Liveline on RTÉ Radio 1 on Friday, telling listeners that he would be away making a new television series.
At the end of aweek that saw Liveline listeners donate €500,000 to LauraLynn, Ireland's Children's Hospice, Duffy told listeners: "Katie Hannon will be with you from Monday because I'm off to film a new, six-part TV series, which I can't tell you about, I'm told.
"But all I can say is I'm proud to present it, because of the work of the previous presenter of the same series."
"And, by the way, again, a million thanks to the half a million that the Liveline listeners have raised for LauraLynn this week," he added. "It's a fantastic achievement."