Morbid update after hero brother saved sister from drowning on a Florida beach

A severed head found washed up on a beach belonged to a teenager who drowned after heroically saving his sister.

Victor Enrique Castaneda Jr, 19, and his sister, Hailey Clements, got in to trouble while swimming at South Point Beach in Miami on November 9.

The siblings were dragged out to sea by a rip current and Victor 'threw' his sister away from the dangerous waters before disappearing beneath the waves.

His last act was enough for two other swimmers to reach her and bring her to shore safely without injury.

Police searched frantically for Victor but he was never found alive, and his family hoped they would at least be able to recover his body.

Then on Tuesday a severed head washed up on Key Biscayne, an island off the coast of Miami, shocking beachgoers after it was found by a worker raking the sand.

Police took the grisly find for examination by the medical examiner and did not initially make the connection to Victor's drowning three days earlier.

Detectives didn't even rule out homicide as an explanation for how the head got there.

But by Friday they confirmed the head belonged to Victor, though the rest of his remains are still lost to the ocean.

'The Miami Beach Police Department extends prayers and condolences to the family,' said Cmdr. Shantell Mitchell said.

'Our victim advocates will continue to provide support to the family during this time.'

Police said they would continue to piece together exactly what happened to Victory after his sister lost sight of him, to give his family closure.

Victor's older sister called him 'the best part of the family' and praised his selfless sacrifice that saved Jessica's life.

'A hero - life has a way of taking the best people. There was a time when he was all that kept this family going. Pure, genuine, so full of life,' she wrote on Instagram.

Another older sister, Jessica, 34, posted photos in memorial of the beloved brother who saved Hailey's life, sharing her 'insurmountable' pain.

'My heart is completely and irreparably shattered. Your absence will never be accepted. No words could ever describe how much I love you Victor,' she wrote.

'To the top of the highest mountain and to the depths deeper than the titanic, I love you little brother. I love you so much.

'I will miss you every second of every minute of every single day for the rest of my life.

'I will dream of your smile and your infectious laugh until I find you in the next life, in every life I will find you.'

Victor's family collectively mourned him on a fundraiser for his funeral that has amassed more than $26,000 in donations.

'He died a hero, using all his strength to save his sister from drowning,' they wrote.

'Even before this, Victor was a hero in every sense. He sacrificed his dreams to join the army, all to provide a home for his family.

'Serving others was always his true calling.'