Two brothers Pita Latu, 34, and Maka Latu, 31, of Mataika, Tongatapu were allegedly drunk while they were fighting on Tuesday 26.
Pita was injured and he was later confirmed dead at Vaiola hospital.
The family reported the fight to Police at around 11pm.
Police immediately arrested Maka and he was charged in relation to the death of his older brother.
He remains in Police custody.