Police have revealed that the woman killed on the A47 on Sunday may have been deliberately pushed in front of an oncoming vehicle.

A man and a woman were killed at around 2.15pm on Sunday as they walked along the eastbound dual-carriageway A47 at Terrington St John, near King's Lynn, and were in collision with a silver Kia.

This evening Norfolk police confirmed the incident was being treated as suspicious.

Post mortem examinations carried out this afternoon revealed the man died from severe head injuries while the woman suffered multiple injuries, both consistent with being involved in a collision with a vehicle.

Detective Chief Inspector Paul Durham, from the Norfolk and Suffolk Major Investigation Team (MIT), confirmed the focus of the investigation was the possibility the woman was forcibly pushed into the carriageway.

DCI Durham said: 'Although our investigation is in its early stages, initial enquiries have given me sufficient cause for concern that this was more than just a tragic accident.

'As a result I'm appealing to anyone who was in the area at the time and may have witnessed the collision – or seen the two pedestrians shortly before the collision - to come forward, no matter how insignificant the information may seem to them.'

The man is described as white, 6ft 1, of slim build with short dark hair. He was wearing blue denim jean shorts and a grey t-shirt.

The woman is described as white, 5ft 7, of slim build, with long auburn coloured hair. She was wearing a bright pink t-shirt and black knee-length leggings. It is believed that both may have been walking barefoot for some time in the general direction of King's Lynn.

Police shut the south-bound carriageway for more than seven hours at Terrington St John between King's Lynn and Wisbech near the petrol station.

Eye-witnesses reported seeing two people walking hand in hand along the stretch of road before the collision.

'They were walking hand in hand, side by side, down the A47 between the petrol station roundabout and the junction with Broadend Road,' said driver Gavin Caney.

'The man was wearing a black leather jacket. She had jeans on. They both looked mid-20s to early-30s. They were walking towards King's Lynn, facing oncoming traffic. They were inches from the road. They just appeared to be going for a Sunday stroll.'

Anyone who saw the crash should ring police on 101.