A British farm has urged visitors to stop posing naked for photographs in its field of sunflowers.

The owners of Stoke Fruit Farm on Hayling Island, off England's south coast, issued the unusual request on social media, having noticed a growing number of visitors stripping naked to pose for pictures among the blooms.

In a post on Facebook earlier this month, the farm wrote: "Reminder to all we are a family area and please keep your clothes on in the sunflowers! We are having a increase of reports of naked photography taking place and this must not happen during our public sessions please!"

Sam Wilson and sister Nette Petley run the farm that their grandfather set up. It comprises 350 acres, producing wheat, peas, potatoes, pumpkins, squash, sweetcorn, hay -- and sunflowers.

Wilson told CNN Friday that there had been about six incidents of people stripping off among the sunflowers since the field opened to visitors at the end of last month.

"We've always had people take risque pictures but this is the first year it's been a problem, which is why we've put signs up," he said.

Wilson added that he and his team decided to put signs up around the farm after "a couple of children saw what was going on."

He said: "We are a really free and happy farm but we just can't have nudity in public view."

Petley added: "It's a really happy and fun place and it does give you that empowering feeling, but it's about the people around and being respectful of that.

"The site is huge and there are so many places that you can hide away without anyone finding you for over an hour, but these incidents were blatantly public."

The sunflowers were first planted by Wilson and his then-fiancee behind the church where got married six years ago. But the plants did not bloom in time for the nuptials.

Wilson said: "We went away on honeymoon and then my sister rang and said 'people want to pick your flowers,' so we set up an honesty box for visitors."

Nothing could have prepared them for just how popular the attraction would become, with people traveling large distances to see the flowers in bloom.

Today, paying visitors are invited to wander around a massive area of about 50 acres, covered by two million sunflowers, said Wilson.