A green space in the city centre has closed to the public after a string of antisocial behaviour incidents.

Brighthelm Gardens, in Queen's Road, is owned by the Brighthelm Centre but other people were allowed to use it.

But the popular open space has now been fenced off after being plagued with rampant drug use, assaults and antisocial behaviour.

The Argus: The green space is kept behind a covered fenceThe green space is kept behind a covered fence (Image: Andrew Gardner / The Argus)

Katie Love, general manager of the Brighthelm, a community centre and venue, said she had to act after a member of her security staff was threatened at knifepoint for asking a group of people to move on.

"There came a point where we didn't have control of the garden and that was scary for me," she said.

A 6ft high opaque fence has been installed round the park.

The Argus: A security guard standing at the only entrance to the gardenA security guard standing at the only entrance to the garden (Image: Andrew Gardner / The Argus)

Now visitors to the green space must have a reason to be there. Katie said this was a last resort.

She said: "We have had security in place on an ad-hoc basis for the last two years.

"There was a huge issue with drug dealing. We can't have people picking up needles, poo or using the toilets to shoot up drugs. It was rife.

"Whenever we felt the situation was getting bad, the security would come and do patrols of the garden. But the problem is that our garden has four exits so any time we approach people they can leave through any one of four ways.

"The security firm we were using didn't want to come back as it felt impossible to secure an unsecured piece of land."

She said on the afternoon of April 22 a security guard was threatened at knifepoint after urging a group of people to leave the park.

The Argus: The gardens can still be used by people inside the Brighthelm CentreThe gardens can still be used by people inside the Brighthelm Centre (Image: Andrew Gardner / The Argus)

The gardens and nearby community centre are used by a range of organisations. Katie said: "Brighthelm has a lot of vulnerable people, charities and support groups and it is my duty to keep them safe. If you are coming to the centre you don't want to walk past people threatening you and causing trouble.

"I had to do something dramatic, reactive to a security threat."

John Lane, chairman of the Brighthelm trustees, said the move was a last resort.

In recent years, the organisation has ramped up its security operation with additional CCTV, meetings with support organisations and the police but "none of these have been sufficiently effective".

The Argus: A sign on the fenceA sign on the fence (Image: Andrew Gardner / The Argus)

The fence surrounds the garden on all sides, blocking access to it from Queen's Road, Church Street and North Road.

A single gate, manned by a security guard, is used near the top of North Road. This means the park can no longer be used as a thoroughfare.

Alongside the fence, private security has been employed to man the gates temporarily though The Argus understands the restrictions on the general public will be eased soon.

Sussex Police have been approached for comment.