The object thrown at horses racing in last week's New Zealand Trotting Cup at Addington Raceway may have been a pen, not a knife as earlier reported.
Addington Raceway chief executive Shane Gloury earlier said a patron reported seeing a man throwing a kitchen knife from the corporate area during the last 100m of the race last Tuesday.
The raceway says film footage shows a shiny object flying 25 metres across the track during the last moments of the race.
Mr Gloury says another patron has now contacted him to say it was a metallic pen and he can identify the person who threw it.
Ricky May, who drove Monkey King to victory at the meeting and says he was too focused on the race to see the projectile.
Mr Gloury says any metallic object thrown during a race could cause considerable damage and injury.
He says the matter is still of serious concern and criminal charges could be laid.