A 26-year-old Timaru woman, who was a pillion passenger, remained in intensive care in Dunedin Hospital last night in a serious condition. She was airlifted to Dunedin with serious injuries following the crash and her name has not been released by police.
Central Otago police sub-area commander Senior Sergeant Ian Kerrisk said police had a "clear picture of what occurred," but declined to give any further details as the matter was now before the court, except to say that alcohol was not believed to be a factor.
Police were asking the public for information about the movements of a dark-coloured Nissan Pulsar with a single female occupant, travelling south from Omarama towards Cromwell between midday and 2.15 on Monday.
"We believe that this vehicle was following a white station wagon a short time before the crash happened. We would like the driver of that white station wagon to contact police," Snr Sgt Kerrisk said.
Any witnesses who saw a group of 8-10 motorcyclists on Harley-Davidson motorcycles travelling from Cromwell towards Omarama around the same time on Monday, were also asked to contact police.
A Cromwell police spokesman said they had received a "steady stream" of calls from members of the public yesterday about the incident.
The crash happened about 19km north of Tarras on State Highway 8, near Goodger Rd.