Police have now located and spoken with the man that was believed to have been at the scene when the stabbings took place.
Detective Senior Sergeant Neil Forlong, officer in charge of the investigation says: "Officers have spoken with the man and have taken a formal statement from him. We are starting to get a clearer picture of what has happened, however we are still making further inquiries and are keen to hear from anyone else that has any information."
The incident happened at a domestic dwelling and it appears that alcohol may have been a factor.
The man that was in a critical condition at Whanganui Hospital is now in a stable condition.
Approximately 12 Police staff including ESR staff are working on the investigation.
If anyone has any information relevant to the investigation please contact the Whanganui Police on (06) 349 0600. Alternatively, information can be provided anonymously via Crimestoppers on 0800 555 111.
Please note that Detective Senior Sergeant Forlong is not available for media requests. Further updates will be released once more information becomes available.
Media enquiries should be referred to Communications Manager Sara Stavropoulos on 027 702 0850.