ENVIRONMENTAL health bosses have warned staff at Southampton Football Club to clean up their act after 50 guests came down with a 24-hour sickness and diarrhoea bug.

Officers from Southampton City Council Environmental Health unit have carried out tests at St Mary's stadium after people reported violent sickness following recent charity and corporate events held in the ground's plush hospitality suites.

Health chiefs are awaiting results of samples to confirm what illness people have suffered - but it is thought to be the notorious 24-hour Norwalk infection.

Saints' catering department came under scrutiny after a member of the public reported sickness to the environmental health team following a meal at the club.

Norwalk - that often occurs in outbreaks - is an intestinal illness causing severe vomiting and diarrhoea and passed in the stool of infected people.

It is understood that about 25 people were struck down following events held at the club on April 9 - these included the Orchid ball held by Netley Abbey residents in aid of the tsunami relief fund.

A further 25 are believed to have become ill after events on April 11 and 12 when Southampton Institute held its two-day staff conference at St Mary's.

A Southampton City Council spokesman said: "The city council has inspected areas at the stadium including the kitchens following reports of a number of people becoming ill following several events.

"The club has been advised to take action including making sure any staff who are ill stay at home and cleaning procedures are properly carried out, and a watch will be undertaken by the council in coming weeks.

"The council has also taken some samples which will be tested to confirm the nature of the illness."

Bosses at St Mary's said the bug is thought to have been brought in by a guest and had affected staff.

A club spokesman confirmed: "There has been a minor viral stomach infection among staff at the stadium.

"This is an issue that Southampton Football Club takes very seriously and as such the environmental health officer was fully involved at the earliest possible juncture.

"The environmental health officer determined that a virus had been introduced to the stadium by an infected visitor.

"The environmental health officer was completely satisfied with the standard of food hygiene at the stadium and the safety of working practices.

"They recommended various steps to control the infection which were put in place immediately.

"They are now hopeful that the virus has been contained although they will continue to monitor the situation."

If tests do confirm the presence of Norwalk it will not be the first time Southampton people have suffered from the highly infectious bug.

Emergency measures were introduced at Southampton General Hospital last autumn when about 30 patients contracted the disease.

Three wards were closed to new admissions in an attempt to control the spread.

In 2003 about 600 of the 1,800 passengers on board Southampton-based P&O cruise ship Aurora were laid low by the bug, also known as the Norovirus. It sparked a diplomatic incident when the ill-fated ship docked in Gibraltar leading to Spain closing its border with the Rock to ensure the virulent virus did not spread.

Regional director of the Health Protection Agency (HPA) South East, Dr Graham Bickler, said: "Norovirus spreads readily in closed environments such as hospitals, residential homes or schools.

"In most cases there is no benefit in someone with this type of gastrointestinal infection being in hospital. People with the condition should stay at home, take plenty of fluid until the condition passes and, if the illness persists, contact their family doctor or take advice from NHS Direct.

"Thorough hand-washing is vital in preventing the spread of infection and this is particularly important after toilet visits. Anyone with norovirus should avoid mixing with others and handling food."