Yemen's Houthi group said on Tuesday it has released a Saudi prisoner, according its TV channel, Al-Masirah.
He had been released on humanitarian grounds due to illness and was repatriated by Red Cross plane, Al-Masirah said, citing Abdulqadir Murtada, a Houthi official.
The United Nations special envoy to Yemen Martin Griffiths welcomed the release on Twitter, saying he hoped to see "more similar humanitarian gestures from the parties," and looked forward to implementation of a prisoner exchange agreement.
Yemen's warring parties are yet to agree full terms of a prisoner swap, one of the least contentious confidence-building measures U.N.-sponsored peace talks held in December's in Sweden amid Western pressure to end the conflict.
The United Nations is pushing for the exchange and a peace deal in the main port city of Hodeidah to pave the way for a second round of discussions to end a nearly four-year-old war that has killed tens of thousands of people.