Ronald Ahrens, 50, was out with 12 other hunters near the northeastern town of Greifswald, 120 miles north of Berlin on Sunday when he was killed by the male boar.
Ahrens, a keen shooter, fired off a round at the 400lb boar and believed he had struck it.
When he went to look for it in some reeds. it suddenly attacked him, goring him with his seven inch long tusks.
He suffered severe injuries to one thigh, toppled into water and lost a massive amount of blood.
Ahrens was a part time supervisor of the nature reserve where he met his end and had been a hunter since his teens.
Recently the region’s agricultural ministry had placed a £25 bounty on every wild boar shot dead in a bid to reduce the spread of African swine pest fever affecting wild animals in the area.
Ahrens was pulled from the water by a member of the shooting party and flown by helicopter to a local hospital where he died.
Mild winters over the past several years have caused a huge rise in wild boar numbers.
Experts advised people not to attempt to try and go after the boar which killed Ahrens incase it was wounded and, therefore, highly dangerous.
“Wild boars are the winners of climate change and agricultural and energy policies,” said hunting expert Torsten Reinwald.
About 500,000 wild boars are killed every year in Germany – not enough to keep the population from growing.