Grave concerns are held for a woman, believed to be pregnant, and a man who may have jumped into a croc infested river to escape police after they ran from a roadblock near Mary River Saturday morning.
Police say the couple may have jumped into the Mary River, on the edge of Kakadu National Park, and have not been seen since, said news.com.au.
Raphael Woodhouse, 25, who has previously been wanted by police in relation to alleged drug offending, and Caitlyn Munnich, 19, were pulled over at a road stop in the early hours of Saturday morning on the Arnhem Hwy.
Ms Munnich is also known to police.
A police spokeswoman could not confirm what time the couple were pulled over, but said they fled on foot from their car towards the nearby Bird Billabong.