The 25-year-old plunged to his death on Mount Taranaki in the North Island yesterday with a companion, also French, who sustained only minor injuries, police said.
They said Roucher, who had been in New Zealand for six months, was near the summit of the 2,518-metre peak when he fell.
Taranaki area commander Inspector Keith Borrel told Fairfax New Zealand that it appeared Roucher had lost his footing in icy conditions on the dormant volcano.