Norwich's biggest nightclub has lost a court battle with the city council in a row over noise.

Mercy nightclub on Prince of Wales Road took Norwich City Council to court to appeal against an order to turn their music down, but the case was rejected yesterday.

The club, which partly reopened on October 27 as part of a �2m revamp, will now have to reduce the amount of noise passing into a neighbouring flat on St Faiths Lane.

City hall officers began an investigation in May when someone living in the flat complained they were being kept awake at night by sound of the bass.

On July 5 owner Steve Peri, who also owns Rocco's, Pulse and Lace, and operations manager Toby Middleton, were handed a noise abatement notice by the council's environmental protection officer, Tony Shearman.

The club then asked sound engineer Richard Vivian, from Big Sky Acoustics, to carry out his own investigation into the amount of noise seeping into the flat.

At Norwich Magistrates Court yesterday Mr Vivian criticised the way the council had measured the noise and questioned why no sound survey was carried out in 2008 when the former offices on St Faiths Lane became flats.

And John Dagg, acting for Mercy, said the sound passing through the wall into the home was not excessive.

He told the court problems only began after city planning chiefs gave the go-ahead for homes in 2008.

But David Lowens, acting for the council, questioned why more soundproof work was not being carried out at the club as part of its refurbishment, after Mr Middleton told the court there were 15 to 20 builders on site.

Mr Lowens said Mr Peri appeared to have enough money to improve the building.

Dismissing the appeal, District Judge Peter Veits said he had not been convinced that Mercy had done all it could to reduce the noise following the abatement notice.

The club will also have to cover the council's court costs of �6,632.

After the ruling a spokesman for Norwich City Council said: 'The evidence presented at court today clearly demonstrated that there were sufficient grounds for the city council serving a noise abatement notice on the premises.'

Mercy, which is expected to fully reopen next Easter as it becomes four separate venues including a VIP lounge and a cafe, refused to comment last night.

• Norwich City Council also confirmed Mercy had reopened without getting planning permission to change the front of the building and put a new sign up.

A spokeswoman for the council said they had told Mr Peri he needed to put an application in.