Christchurch police have re-issued an appeal for information, over the assault of an elderly man on the popular Rapaki track last month

A man in his 70s was assaulted by another man on Summit Road, at the top of the track, overnight on July 20.

Police say the incident occurred between 11pm and 7am.

The offender is described as a Pakeha in his early 30s, who was driving a light beige or grey older-style van, and had two aggressive dogs - possibly part Doberman - with him.

The victim remains in hospital with serious head and facial injuries.