A police chief confirmed 'with some degree of certainty' that a woman pedestrian was pushed to her death in Sunday's double fatality on the A47.
Det Chief Insp Paul Durham told a news conference that both pedestrians were Lithuanian – and in their 20s- but their names were being withheld until next of kin had been informed.
Police remain unclear how the man came to die – they are still unsure whether he jumped or stumbled in front of an oncoming car.
'Whether he did it on his own part or stumbled are things we need to deduce,' he said. 'But I can say with some degree of certainty he pushed her. What we need to find out is why?'
He also revealed that various sightings of the couple – both in their 20s- were being gathered by police.
'They would have posed an unusual sight – the woman wearing a bright pink vest-top and the man in designer-style jean shorts – both walking barefoot along one of our busiest trunk roads on one of the hottest days of the year,' he said.
'We need to find out how and why this tragedy occurred and I would urge anyone who thinks they may have seen them in the area, at any time on Sunday morning, to come forward with information.'
The earliest sighting was at 12.30pm at the Elme Hall Hotel roundabout with the A1101 and A47.
At 1.20pm the couple went into Worzals garden centre at Walpole Highway, off the A47.
'Both of them calmly said 'call police'' said Det Chief Insp Durham. 'The lady in the shop went to get help but they walked off.'
He said the collision took place at about 2.15pm and police were called minutes later.
The police chief said both had been struck by a Kia near Terrington St John – an earlier reference to a BMW involvement was now being discarded. In the immediate aftermath it was unclear which vehicle had struck them.
The man is described as white, 6ft 1, of slim build with short dark hair. He was wearing blue denim knee-length 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 vest top 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 are keen to get sightings of the pair from before 12.30pm and have launched an appeal for witnesses.
Anyone with information is asked to call Norfolk Constabulary on 101 or alternatively pass information via the Crimestoppers charity on 0800 555111.
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