Police said yesterday it was a one-vehicle crash and the dead person was the sole occupant.
This morning, police said they are now seeking any witnesses who spotted at least two vehicles travelling together in the Palmerston North or Newbury area around 3.20am on Sunday.
Ross said the vehicles of interest are a blue Mazda Demio and a white Nissan Tiida.
The incident happened along a straight stretch of rural road, 10km northwest of central Palmerston North.
“If you have any information that could assist our enquiries, please contact police via 105 and reference file number 250914/0242.”