A shocked volunteer at a Spalding nature reserve stumbled across a visitor defecating in the great outdoors.

Volunteers regularly sweep up human excrement at the Vernatt's site - once in the middle of a public footpath - but this is the first time someone has been caught in the act.

Volunteer Pete Boekestyn challenged the squatting man but says he simply said "my problem" and carried on regardless.

Why do this in a treasured nature reserve? (16797116)

Pete said: "To say he didn’t give a damn about being caught is an understatement - he literally ignored me and carried on pooing and talking on his phone! I don't know if the person on the other end of the phone knew what he was doing."

Pete warned the man he would take a picture and, again, says the man was completely brazen and didn't care.

Since the man's picture was posted on social media, one or two people suggested he might have defecated because he was ill.

A grot-spot before the volunteers moved in ...

But Pete sawthe man striding around the reserve before and after the event, and says he was perfectly fit and well.

Pete began volunteering at the site around nine months ago and he and a team of like minded people have given the reserve a new lease of life.

Initially there were both drug and dogging dens but Pete says they have now gone because the volunteers have been so proactive.

There is still evidence of drug-taking at the site, as volunteers find paraphernalia here and there, and one person reported a seeing couple engaged in sexual activity up against a tree one morning.

The transformed grot-spot after volunteers cleaned up

The site remains a magnet for illegal anglers despite fishing in the Vernatt's being banned all year round.

Pete believes the anglers are mainly to blame for the human excrement on the reserve because they spend hours at a time fishing and then go off to a spot to relieve themselves.

A team of eight to 10 adult volunteers, and youngsters known as "mini-pickers", have systematically cleared the nature reserve of rubbish.

Ten bins have been placed at key spots and most visitors throw their rubbish in the bins.

Pete says: "Ninety-seven per cent of the rubbish is now in the bins.

"It's been a fantastic achievement all the way round to make the nature reserve a place where people want to visit.

"Before Christmas I would not go near the place - it scared me to death because of the drinking and the drug taking."