One person died and eight others were taken to hospital after eating contaminated meat.
The victim was identified as Chege Gathumuni, 40, from Nyanduma, Kiambu.
His widow, Jacinta, said he started complaining of stomachache shortly after arriving home from the shopping centre where he had eaten the meat.
“He started to complain of stomach pain and we took him to a clinic where we were advised to take him to Kiambu hospital but he died on the way,” she said.
Those hospitalised are said to be in stable condition. Unconfirmed reports said more than 20 people were treated at the district hospital and discharged.
“The meat was eaten by about 150 who had attended a burial ceremony and most of them have travelled back and we do not know if the meat affected them,” said Mr Gabriel Waruinge, the local chief.
Mr Waruinge said a health officer who inspected and certified the meat fit for consumption and the butcher who sold it had been arrested.
Mr John Mwai, a veterinarian, who was treating the animal for anthrax, said he had warned the locals against eating the meat but they ignored him.
The butcher is alleged to have slaughtered the animal and sold the beef to unsuspecting customers.