Corrections confirmed on Tuesday Butler was on a community-based sentence after a request from NZME considered under the Official Information Act.
It is believed Butler was on home detention.
Read more: Police name man at centre of homicide investigation
A homicide investigation was launched after Butler was found dead and another man in his 50s was found seriously injured.
The second man was taken to Whanganui Hospital and was reported to be in a stable condition.
A post-mortem examination was expected to be completed on Wednesday.
Police have asked anybody with information to come forward.
Anyone who may have information is asked to contact police by calling Crimestoppers on 0800 555 11.