POLICE are trying to trace two potential witnesses to an early morning raid at a Rugeley supermarket.
They want to hear from two people using a cashpoint outside the shop at the time.
The robbery at the Co-op store, Queensway, happened at around 5.45am on Monday March 31.
The offenders were lying in wait as staff were opening up at the store.
The four staff members were threatened with a knife and locked in a toilet while the offenders broke into the shop's safe and stole a substantial amount of cash.
A police spokeswoman said: “Our investigation into this incident is continuing and we now know there were two people using the cash machine outside the store at the time of the incident.
“We’re appealing to these two people to contact us as they may have information that could help us.
“They may not have been aware of what was happening in the store but may have seen the offenders, or a suspicious vehicle, at some point.”
One possible witness is described as a white woman wearing a dark green top, who was driving a dark coloured Mk2 Toyota MR2 with pop up headlights.
The second was a white man wearing a dark coloured three-quarter length zip top similar to a fleece, blue trousers and white shoes or trainers. He was driving a dark coloured medium sized hatchback, similar to a 2000 to 2005 model Vauxhall Astra.
If you think you are either of the people described above, or you know who they are, please contact DC Paul Whitehouse on 101, quoting incident 64 of March 31. Alternatively, you can contact independent charity Crimestoppers, anonymously, on 0800 111555.