A gunman who stole £200 from an Oxford petrol station may have slipped up by leaving a trail of footprints in the snow.

The robber went into the BP garage, in Cherwell Drive, Marston, at 7.50pm on Friday and threatened a member of staff with what was believed to be a gun.

After grabbing the cash, the robber jumped over a nearby fence and ran off along Marston Road towards the city centre.

Staff member Senthil Lakshmanan said: “He picked up the money and ran away.

“He jumped over a fence to get away, but he left the prints of his foot in the snow. The police told us not to touch them and they came and looked at them.”

Police said they had not ruled out a connection with a recent spate of robberies in Oxford, which included raids on off-licences and betting shops in Headington.

Mr Lakshmanan, who was not on duty at the time of the incident, said the cashier who was confronted by the robber had been left very shaken.

He said: “There were two people working, one on the filling and the other on the shopping. It was very quiet at that time.

“I think he was a bit scared — he couldn’t do anything. He’s just started. He studies at Oxford Brookes and works here part-time.

“It only took a few seconds. The robber came in, showed the gun and got him to open up the till.”

Mr Lakshmanan said police had also taken CCTV footage of the robbery.

Bradley Rowland, the supervisor at the Balfour store opposite the garage, said: “No-one heard a thing. There were a couple of people working in the shop, and they were getting ready to close at 9pm.

“We’ve had this man with a gun going around Headington recently and there have been a few incidents here in the past few years.

“I think it’s because we’re in an area that’s so close to the bypass. It’s so easy to run away from here or get away into town.”

The robber was in his mid-20s and was wearing dark clothing.

Det Sgt Russell Simpson said: “We’re still in the early stages of the investigation, but are keeping an open mind as to whether this incident is linked to the other armed robberies in Oxford in December and January.”

Anyone with information should call Det Sgt Simpson on 08458 505505 or Crimestoppers on 0800 555 111.

l The heaviest snowfall of the winter so far, driven along on gale-force winds, is forecast to affect Oxfordshire later today.

About 20cm (8in) of snow is expected to falltonight.

The Met Office said there would be a mixture of rain, sleet and snow today, with the heavist snow falling after dusk and the risk of drifts building up due to the wind.