Autlan:   Inspectors are collecting soil, water and produce samples, reviewing export logs and combing packing plants in three major tomato-growing states in Mexico.

But the US Food and Drug Administration (FDA) appears no closer to finding the source of a mysterious salmonella outbreak that has sickened more than 900 people nationwide.

The FDA is not even 100 per cent sure that tomatoes are the cause - it added peppers and cilantro on Saturday to its list of foods under investigation in the outbreak.

A team of three FDA inspectors has gone through five farms in the western states of Jalisco and Sinaloa in the past two weeks, looking at all aspects of tomato production: the greenhouses where they are grown, the packing plants where they are shut into boxes, the shipping methods for the trip north to the US.

The results can't come too soon for the three Mexican states that were targeted by the FDA, along with farms in Texas and Florida.

Facing big losses

Bonanza 2001 farm in Autlan, Jalisco, which normally exports about 12,000 tonnes of tomatoes a year to the US, has hundreds of tonnes sitting in a warehouse near the Texas-Mexico border as demand has plummeted, said spokesman Luis Almejo.

They may rot.

Sinaloa growers also face big losses.

"We're demanding that they release those results as soon as possible so that Sinaloa can be cleared of any suspicion," said Manuel Tarriba, president of Sinaloa's Tomato Growers Association, adding that he expects some results by the end of next week.