The 18-year-old was arrested late on Monday at a Sue Cr house in Coledale and taken to Tamworth Police Station where he was questioned by detectives.

He was charged with one count of recklessly causing grievous bodily harm and police will allege he assaulted a 32-year-old man in Green St in the early hours of Sunday.

He was refused bail to front an out-of-sessions hearing in Tamworth Local Court on Tuesday morning.

THE man injured in a wild brawl in Coledale remains in a critical condition in a Sydney hospital with head injuries.

The 32-year-old was flown to John Hunter Hospital in Newcastle on Sunday afternoon after he was found in Green St about 1.30am.

Police said he had been struck in the head with a brick and a bottle and suffered a fractured skull.

He was assessed by doctors before being airlifted to Sydney where he remains in a critical but stable condition.

Detectives spent a second day on Monday interviewing witnesses.

Investigators have spoken to several people and on Monday continued to take statements about what happened in the lead-up to the attack.

Police and paramedics were initially called to Green St after reports a brawl broke out before the man was discovered injured in the street.

Detectives believe more people know what happened and are urging them to come forward.

Anyone with information is urged to contact Tamworth police on 6768 29999.