After spending six weeks in hospital being treated for anaemia, parasites on his skin and a head injury, Jervis, a 100-kilogram green turtle, has been released into Sydney Harbour.

Jervis, a 100-kilogram green turtle, was released into Sydney Harbour following a six-week recovery in Taronga Wildlife Hospital. Credit:Taronga Zoo

The reptile was found washed up at a beach on NSW's South Coast in May.

He spent a month and a half recovering at Taronga Wildlife Hospital and was released just outside Sydney Heads on Thursday.

"He was very sick," Taronga senior veterinarian Dr Larry Vogelnest said.