Police, alongside emergency services colleagues, attended the scene of a two-vehicle collision on Ballygawley Road, Dungannon just after 9.20am on Saturday, 14th December.
The drivers of both vehicles were taken to hospital for treatment to serious injuries.
The driver of one of the vehicles, a man aged in his 80s, remains in a critical condition at this time.
Sergeant Fletcher said:
"Police would appeal to anyone who was in the vicinity of the Ballygawley Road at the time and saw the vehicles involved, a black Volkswagen Golf and white Vauxhall Insignia, to contact them on 101, quoting reference 479 of 14/12/24.
"We would be particularly keen to hear from anyone who may have recorded dashcam or other footage of the collision, or the events leading up to it."
Alternatively, you can submit a report online using the non-emergency reporting form viawww.psni.police.uk/makeareport/
You can also contact Crimestoppers anonymously on 0800 555 111 or online at http://crimestoppers-uk.org/