A 23-year-old Galiwinku man who died while helping save three girls from drowning off the Northern Territory's Elcho Island has been awarded a posthumous bravery medal.

Police Commissioner Reece Kershaw said the Aboriginal man, who cannot be named for cultural reasons, showed courage and conviction when he helped save three girls at Galiwinku in 2012.

The 23-year-old is one of six men awarded medals for the 2012 rescue of the girls who became caught in a rip caused by the incoming tide and a rapidly approaching storm at the island, about 515 kilometres east of Darwin.

The man and Eddie Dhurrkay swam out to get the girls and successfully brought them back to shallow water, but continued to struggle to bring them ashore.

They were helped by NT Police Remote Sergeant Josef Hart and Dr Peter Power.

Constable Ben Parfitt and Henry Burarrawanga were working on a police vessel and called into help.

Upon their arrival, Mr Burarrawanga saw a girl floating in the water and jumped in, with help from Sergeant Hart and Dr Power to bring her to the shore.

Shortly after successfully getting one of the girls to shore, the 23-year-old man was lost underwater and drowned.

Eddie Dhurrkay received his bravery award from the NT Police chief Reece Kershaw at a ceremony on Elcho Island. ( Supplied: NT Police )

Mr Dhurrkay was presented a Silver Medal, Constable Parfitt and Mr Burarrwanga were presented Bronze Medals, while Sergeant Hart and Dr Power received Certificates of Merit, all from the Royal Humane Society of Australasia.

Commissioner Kershaw said all of the men showed "selfless dedication to helping our mates and looking out for our children".

"When these men acted immediately to save the lives of three young girls who were in a perilous situation they displayed the courage and conviction they were doing the right thing," Commissioner Kershaw said.

"They may think and believe they are not heroes, but in my view, and the view of many, they are," Commissioner Kershaw said.