The documentary's lead actor Mahmoud Mansouri received the prestigious UK award, realscreen.com reported.
The world's biggest global gathering of natural world storytellers presented the award to Amiri's doc on the discovery of a rare and unique snake called the Spider-tailed Horned Viper.
The film narrates the story of the discovery of the viper in western Iran by Mansouri who is a native farmer and has provided the production team with information about the viper and its nests.
The creature is a species of viper native to western Iran.
London's Keo Films took home three honors at this year's awards ceremony for the feature documentary 'Rise of the Warrior Apes', including the WWF Golden Panda Award, the Script Award and Films at 59 Sound Award.
Held in Bristol, the biennial event Wildscreen Festival brought together more than 900 filmmakers, photographers, broadcasters and content creators, from over 40 countries, for an unrivalled program of 130 events, featuring 180 industry thought-leaders.
The 2018 Wildscreen Festival was held in Bristol, southwestern England.