Frank Varey's body was found on Thursday night (July 22) more than five hours after a search was launched in the River Dee in Chester.
He was reported missing at about 2.30pm, before Cheshire Fire and Rescue Service confirmed they had found a body at 8pm.
Today (July 23), Varey's family, friends and members of the public gathered at the river to release balloons in his memory.
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Following the memorial, his parents, brothers and sister paid tribute to the 16-year-old, describing him as a "legend in the boxing world and in life".
"We are devastated beyond words," they said.
"May our Young King live on forever."
Many have paid tribute to the boxing star - who recently represented England at the European Junior Championships 2019 in Galati, Romania.
Writing on Instagram, world heavyweight champion Tyson Fury said: "RIP Frank. Was a future world champ. May God be with your family."
Olympic gold medalist Luke Campbell MBE also paid tribute to the young star on Twitter, posting: "RIP Frank Varey. Rest well champ, thoughts with all your friends and family."
The emergency services had been searching the river near Lower Park Road, with the river bank and Queen's Park suspension bridge closed as part of the search.
In a statement, Chester Police said: "Search teams found a body in the river shortly before 8pm.
"Formal identification has not yet taken place but it is believed to be that of the missing boy."
It comes as emergency services warned of the invisible, deadly dangers associated with open water after six people drowned in English lakes and rivers over the weekend.
Supt Myra Ball added: "Sadly this is the second river death that we have seen this week in the county.
"This appears to be another tragic accident and our thoughts are with the boy’s family at this very difficult time."
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