May not be 100% what you are looking for but this infamous story relates to the tribal history of my area around the Bay of Plenty in New Zealand where missionary Carl Volkner was accused of being a spy by local Maori

"Despite hostilities Völkner had remained at Opotiki, making several visits to Auckland in 1864, and again in January 1865. Ignoring warnings from several members of Te Whakatohea, he returned to Opotiki in February with fellow missionary Thomas Grace. Arriving on the Eclipse on 1 March, they learned that Völkner's house had been plundered, and were taken prisoner. The next morning Völkner was led to a willow tree some 200 yards from his church. There, wrote Grace, 'He then knelt down and prayed, and, having shaken hands with his murderers said "I am ready", and, while they continued to shake hands with him, they hoisted him up.' Völkner's body was taken down after an hour and decapitated, and the blood tasted, or smeared on their faces, by the many people present. Kereopa forced out the eyes and swallowed them, describing one eye as Parliament and the other as the Queen and English law. This act of indignity to the head of an enemy conferred mana on Kereopa, and earned him the name Kaiwhatu (the Eye-eater)."

http://www.teara.govt.nz/en/biographies/1v5/volkner-carl-sylvius

Kereopa was put on trial and hanged. In 2014 he was pardoned by the NZ government

"Volkner's brutal slaying — reprised in the 1983 film Utu — made news around a shocked world, especially the claim that Kereopa had removed Volkner's eyes with his fingers and eaten them, earning him the name "Kaiwhatu: the eye-eater".

Accounts at the time reported that the cleric's head was placed on the church pulpit while frenzied warriors who witnessed the slaughter danced and yelled. The next day, Volkner's severed head was taken for smoking before it was carried to other places."

http://m.nzherald.co.nz/nz/news/article.cfm?c_id=1&objectid=11278442