Investigators are trying to determine what caused a deadly head-on crash near Cookstown.

The OPP say one person was killed, and a second person remains in serious condition in a Toronto trauma centre.

The collision happened on Highway 89, between 8th and 9th Lines around 7:00 p.m. on Saturday.

Highway 89 was shut down for several hours for the police investigation, but has since re-opened.

Provincial Police have not yet released any further information about the victims.