Ron Newbould was among a group of walkers who spotted the white wallaby on a footpath near a corn field on Saturday, August 15.
Mr Newbould said the wallaby was eating leaves from a nearby hedge and he was able to get pictures and a video of it.
He said: “We were about half way round our walk when following the footpath, we had entered a corn field through a gap in the hedgerow and paused briefly for people to catch up. Looking round my wife saw the wallaby about 15 metres from us calmly eating leaves from the hedge.
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“As we watched it for the next five minutes or so, it posed for lots of photos and video.
“At one point it actually took a few steps towards us, resumed its eating before eventually turning, glancing back at us and leisurely heading off in the opposite direction.”
Mr Newbould, who is from Northampton, said he had been told by local residents that the wallaby may have escaped from a zoo some time ago.
The white wallaby was first spotted in a field near Salcey Forest in Mr Newbould’s hometown earlier this month by Caroline Phillips who was riding a horse in the area.
Ms Phillips, who comes from Australia, also managed to get pictures and take a video of the wallaby.