IT'S the nasty niff that's causing a stink in a Hampshire town.

The pungent pong -which smells like rotten eggs - is even said to be so bad that it has woken people up.

Worried residents have even inundated environmental health bosses, concerned that because it is so dreadful it might even be harmful.

Now an investigation is underway involving Environment Agency officials and Test Valley council to try and get to the bottom of what is causing the Romsey whiff.

Some have pointed the finger of blame on the Squabb Wood Landfill site at Shootash.

But Viridor, which owns the site, says doesn't believe it is it is to blame for the offensive smell.

Viridor's regional manager Tanya Reed said: “Neither we, nor the Environment Agency have been able to locate the source of the odour. There is a smell in the air in the area, but no detectable smell on site.

Thorough investigations have been made on site to identify any possible source, but nothing has been found. We are continuing to work with the Environment Agency.”

She added that officials from the Environment Agency and Test Valley Borough Council had spent some considerable time on the site reviewing possible causes for this odour.

“All parties agreed that no smell or source of the odour could be found on site. All relevant gas extraction and operational equipment are working effectively. Our site manager will continue to work alongside the relevant authorities to help source this odour,” said Tanya.”

But residents are demanding to know what is causing it.

They included Mary Haverly who described it as a “dreadful smell” that is evident frequently in and around the town.

“The smell was so evil and strong one night that it woke my mother and I and my daughter up. It was so obnoxious that we wondered if it could be harmful,” said Mary who lives in Church Lane.

Romsey's MP Caroline Nokes said she has received numerous complaints and has asked the borough council's head of housing and environmental health to investigate.

She said: “It is really quite a marked smell, a bit like rotten eggs, and it would be great if we could find where it is coming from.

"That is only going to be achieved by people reporting it to the borough council whenever they smell it.”

A council spokesman said it was aware of the smell and it was working with the Environment Agency to confirm the source.

The Environment Agency said anyone with concerns or wanting to report further problems to call its 24 hour incident hotline on 0800 807060.