Prince William is in hot water — for murdering Bambi!

Britain’s antihunting fanatics are furious that the 21-year-old Prince killed a tiny deer called a dik-dik with a 7-foot spear while visiting Masai tribesmen in Africa.

“This is the worst kind of publicity for Wills,” a royal insider said.

Bad Wills’ hunting occurred after the heir to the throne took spear-tossing lessons from villagers in Kenya during a month-long African vacation.

The Prince practiced by tossing the deadly spear into a tree, then sneaked up on a full-grown, 14-inch-high deer called a dik-dik — and skewered it with his first toss.

“I was proud of him,” said his mentor, a villager named Legei. “He picked it up by the tail and presented it to me.”

This is not the first time Wills has been blasted for his love of hunting — a sport Princess Di abhorred.

The Prince was just 14 when he shot his first stag at the Queen’s Balmoral Castle estate in Scotland. He was even “blooded” in the hunting tradition when companions smeared the animal’s warm blood over his face.

Wills’ latest expedition took place while he was in Africa visiting his girlfriend, Jecca Craig, daughter of a wealthy conservationist who owns a game reserve there.