The grandmother of a driver accused of leaving a cyclist for dead wept outside court as she said her "gorgeous" grandson was "terribly sorry".

Matthew Terrance O'Connor, 27, of Heidelberg, was arrested last Friday morning at a home in Heidelberg and charged with culpable driving.

He is accused of killing cyclist Peter McGuffie, 54, in a hit and run on Barkly Street, West Footscray on Thursday.

Mr O'Connor was supported in court on Tuesday by a small group of family members.