A man was left with a fractured skull and a bleed on the brain following an incident in Newstead.
Detectives investigating an incident have arrested a 35-year-old man.
It’s believed the victim was struck to the back of his head with a blunt object at a house in Tilford Road.
It happened at around 2am on Sunday, June 6 and was reported to Nottinghamshire Police when he became poorly two days later and was taken to the Queen’s Medical Centre by ambulance.
Operation Reacher crews arrested a man on Thursday (June 10) afternoon. He has been bailed while enquiries continue.
Detective Constable Andrew Sibley, who is leading the investigation, said: “The victim has no memory of being struck and, even though he has been conscious, he remains in a serious but stable condition in hospital.
“The investigation is very much ongoing but our enquiries have uncovered that this is an isolated incident where those involved were known to each other having been together with friends.
“We are speaking to several witnesses and there is no threat to the wider public.
“If anyone has any information that could help, please don’t hesitate to call us on 101.”
People with information can call Nottinghamshire Police on 101 quoting incident 174 of 8 June.
Alternatively, please call Crimestoppers anonymously on 0800 555 111.