"He was one of the best," said a man posted to Papua New Guinea for missionary work with Mr Fungavaka as a young man.
Hauntingly, he recalled seeing a comment Mr Fungavaka once posted on Facebook wondering how he would be remembered after he died.
The man spoke about working with Mr Fungavaka, who loved to help others and had a "God-like" quality: "Something that I loved and I wanted to be like him."
Speakers also talked of the need for forgiveness over the "terrible incident that happened to Kali".
Tongan police said Mr Fungavaka, who was in Tonga to bury his grandfather, was arrested for a minor drunkenness offence after going to a Nuku'alofa club with a relative.
Charges against the officers were upgraded as the murder charges against the civilian prisoner was downgraded to manslaughter.
The trio have been remanded in custody and will next appear in court on September 24.
Today's service reflected the wishes of Mr Fungavaka's wife Audra Watts and those of his wider family, who are members of the Church of Jesus Christ of Latter Day Saints.
Several gathered mourners wore sweatshirts bearing Mr Fungavaka's face and family and children held photos as they walked behind his coffin.
Mr Fungavaka has been described by colleagues as a quiet, humble police officer who was passionate about the job, especially making a difference in the Polynesian community.