Detectives are concentrating on sightings of two speeding motorcycles in their hunt for the Chipping Norton Co-op robbers.

Police said they had received calls from the public and were now certain the motorbikes, each carrying two people, were the robbers making their getaway.

Thames Valley Police spokesman Tim Wiseman said: "We have heard from witnesses both in Chipping Norton and outside the town. There are two areas that have been brought to our attention that have given us a good idea where they travelled to and from.

"We are not going to be releasing those details.

"We would appeal for anyone else who saw two motorcycles with four passengers in total on Monday to contact us.

"People have said they were seen travelling at speed."

Det Insp Phil Murphy, of Banbury CID, added: "It's possible that these men had been to view the layout and entrances to the store before the raid.

"It's also possible these two bikes have been dumped, maybe some distance away,

"If anyone believes they have seen or found a motorbike then they should get in touch."

Anyone with information should call police on 08458 505505 or Crimestoppers on 0800 555111.