Police have identified the man who died as Michael Kearns, 49, of Newquay. His next of kin have been informed.
Police are no longer treating the incident as a murder but said it will be investigated as a major crime.
In a statement issued this morning Devon and Cornwall Police said: "Following an assessment of the circumstances, this is now not a murder enquiry.
"The investigation in to the circumstances leading to the death of the male will continue and will be conducted by officers from our Major Crime Team."
The investigation will be known as Operation Domain. Police now refer to the incident as being outside of the nightclub.
Police said the four people arrested yesterday - originally on suspicion of murder - have been interviewed and released on police bail until late July.
The police were unable to comment on whether any of those arrested were staff from Sailors nightclub, as is understood by thisiscornwall.
The police spokesman said: "Police are continuing with their investigations in particular reviewing CCTV of the area, interviewing witnesses and contacting all persons who were in the nightclub at the time of the incident.
"The police have received assistance in their enquiries from both the Sailors nightclub and the local Newquay community following this tragic incident."
The dead man is understood to be Mick Kearns, a keen angler and caravan owner at White Acres holiday park near Newquay.
Tributes from angling colleagues described Mr Kearns as "a gentle giant and a true gent".
Mr Kearns is reported to have been out in Newquay with friends to celebrate the end of the Milo angling festival held at White Acres.
Fellow angler Simon Fry said on Twitter:"Tragic end to the WA (White Acres) festival week with the news of Mick Kearns death in Newquay last night.
"RIP big man, you will be missed by all."
Anglers gave tributes to their friend on the Talk Angling website. Maver Si said: "Terrible news he was a gentle giant & a true gent... no one deserves this least of all Mick.
The four people arrested yesterday are understood to be staff from the nightclub in which Mr Kearns was found dead.
Police are expected to make a further statement this morning on developments in the investigation.
A man was murdered in a nightclub in Newquay last night.
Police confirmed a 49-year-old man died following an incident at Sailors nightclub on Fore Street.
Police said the man was local and his next of kin have been informed.
The area surrounding the popular bar and club was closed to the public this morning with police and forensic officers on the scene.
Police and paramedics were called to the club shortly after 3am this morning and said the incident took place inside Sailors.
The man was unconscious and not breathing when police arrived. Staff at the club and police officers tried to resuscitate the man until the ambulance arrived.
This morning police were examining a large pool of blood in the street outside the club.
The 49-year-old man was taken to Royal Cornwall Hospital in Truro where he was pronounced dead on arrival.
A spokesman for Devon and Cornwall police said: "Four men have been arrested on suspicion of murder and have been taken to Newquay Police Station."
Anne Marie Phillips from the Upper Crust bakery next to the nightclub spoke of her shock at hearing of the murder.
She said: "There might be a scrap outside the front but nothing like this.
"I'm very shocked - it's absolutely terrible."
Violence in bars and clubs has been a problem in Newquay for a long time. In 2009 the Newquay Safe partnership was launched to bring together police, the local authority and the local community to try and improve the situation.
The Mayor of Newquay, Kevin Towill, said: "I'm shocked and saddened to hear of this news.
"I would like to send my condolences to the family and friends of the victim.
"I'm sure the police will carry out a through investigation into what happened."
Sgt Regie Butler, from Newquay Police, posted on social networking website Twitter: "It is worth reminding people this is very rare in Newquay and the number of assaults fell last year."