A woman has died from botulism after eating sardines at a Bordeaux restaurant and 12 other people, mostly foreigners, are being treated for the rare condition, French health officials said Wednesday.

Botulism is a serious neurological illness typically brought on by eating food that has been improperly preserved.

The city centre restaurant had preserved the sardines itself, the DGS health authority said late Tuesday.

At Bordeaux's Pellegrin hospital, Dr Benjamin Clouzeau said the woman had checked into a hospital near Paris after travelling back  with her partner. She returned  home and died there. Her partner remains in intensive care.

In total 12  people were still receiving emergency treatment Wednesday, health services said. Five were on respiratory support.

They include American, Irish, German and Canadian nationals, he said.

A German travelled home for treatment, as did a resident of Barcelona, Spain, the doctor said.

All of them had eaten at the restaurant, the "Tchin Tchin Wine Bar" between September 4 and 10 when there are typically large numbers of tourists in the southwestern town, famous for  wine and food.

They all had sardines that had been stored by the restaurant owner himself in jars, the DGS said.

- 'Strong smell' -

Botulism is deadly in five to 10 percent of cases because of a toxin that can be generated by clostridium botulinum bacteria when preserved food is insufficiently sterilised.

Authorities were still running tests at the restaurant, the DGS said, adding it could not rule out further cases of botulism which has an incubation period of up to several days.

They were trying to contact other people who may have eaten sardines at the restaurant. A total of 25 people could be affected, they said.

The illness can cause muscle paralysis lasting several weeks, with the most immediate danger stemming from affected respiratory muscles.

An international health alert has gone out asking hospitals to look out for patients who have recently been to Bordeaux and have symptoms including diarrhoea, vomiting or problems with vision or speech.

Anti-toxins from military stocks were being brought to Bordeaux.

Local newspaper Sud-Ouest quoted the restaurant owner as saying he had thrown out some of the jars containing sardines because of a "strong smell" from the containers when  opened.

But others "appeared in good condition and were served up to customers", he said.

The restaurant was closed Wednesday and the owner told to abstain from any more home-made sardine preparations, with the authorities seizing the remaining sardines for further testing.

The establishment, which had never had previous hygiene, will be thoroughly cleaned.