Police have said a samurai sword may have been used in an attack which left a man with a life-threatening head injury.
The 23-year-old from Winchester was found at a property in Eastleigh, Hampshire, at about 22:15 GMT on Friday.
He remains in a critical condition at Southampton General Hospital.
A 17-year-old boy arrested on suspicion of attempted murder remains in custody.
A 17-year-old girl who was also arrested has been told she is no longer suspected of attempted murder.
However, she was rearrested and released under investigation on suspicion of assisting an offender.
Police have been searching for the weapon in the streets between Heinz Burt Close, where the injured man was found, and nearby Scott Road.
Detectives have appealed for residents in the area to check their bins and gardens.
They said a 48-year-old man from Bursledon is no longer suspected of grievous bodily harm but has been rearrested and released under investigation on suspicion of possessing class B drugs.