HOUSTON -- Houston health officials confirmed Friday that they are looking into the death of a man who contracted salmonella after eating tomatoes at a local restaurant.

The cancer patient’s family said they believe the bacteria may have contributed to his death.

Earlier this week, a health warning was issued about the consumption of raw tomatoes because of a rare strain of Saintpaul salmonella.

Officially, Raul Rivera died from complications of lymphoma. His family told 11 News that he became ill after a celebratory meal that included tomatoes.

Rivera and his family dined at a local Mexican food restaurant this week to celebrate his progress in battling cancer. His family told 11 News that recent tests showed he had an improved white blood cell count, which is key in the battle against lymphoma.

After the dinner, Rivera and other family members became ill. Rivera died shortly after.

While the Houston Health Department confirmed that Rivera did have salmonella poisoning, they have been unable to confirm how he was infected or if the bacteria contributed to his death. Health department spokeswoman Kathy Barton said an investigation is under way.

Officials with the Texas Department of State Health Services said the investigation is in its early stages, but consumption of raw tomatoes has been targeted as the likely source of the Saintpaul strain of the Salmonella bacteria. Specific types and sources of tomatoes have not been identified.

Houston and Harris County health officials confirmed that there are 16 confirmed cases of salmonella in the county. Two of those are being tracked by the city health department while the rest are being followed by county health officials.

Rivera is not counted among those cases, health officials said.

As they work to determine the source, health officials are advising that people not eat any raw Roma or full-sized round tomatoes other than those sold attached to the vine or grown at home.

The confirmed cases of Salmonellosis were found in Harris, Fort Bend, Dallas, Tarrant, Hays and Cameron counties. Seven people in Texas had to be hospitalized.