Strike Force Mindoro detectives completed a final examination of the Green Street home in Coledale before the official police tape out the front was removed.

The house has been under police guard since the early hours of Saturday morning when the 21-year-old man was found inside with several stab wounds.

The post-mortem has also been completed on the body in Newcastle, but police are remaining tight-lipped on their official probe.

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"The man's death is still under investigation and we have spoken to several witnesses in the course of our investigation," Oxley Detective Acting Inspector Jason Darcy told the Leader on Wednesday.

"The crime scene has been cleared and a post-mortem has now been completed."

No one has been charged in relation to the man's death, but a woman arrested shortly after for questioning was released without charge on Saturday.

A strike force - made up of Oxley detectives, backed by investigators from New England and across the Western Region - has been piecing together what happened in the moments before the man was critically injured.

Despite emergency efforts to save him, he died shortly after in Tamworth hospital.

It's understood more than 20 people including the man's family and friends have been contacted by investigators, with police still searching for more that were at a house party in the same street.

The people at the party are key to the investigation into finding out what they saw or heard late on Friday night and into Saturday morning.

"Police are still interviewing witnesses but we still have people we would like to speak to who we believe were in the Green Street area on Friday night," Detective Darcy said.

"In particular, there are people still outstanding who were at a house party or nearby and we make another appeal for them to contact detectives."

Investigations are continuing and anyone with information, or who has dashcam or phone footage of the area on Friday night, is being urged to contact Tamworth police on 6768 2999.