Customs officials' claims that the rice seized in Lagos last week was "plastic" sparked confusion and official denials. ...
Tests on samples of the rice showed that it was "unwholesome for human consumption", exceeding the maximum limit for bacteria including "Coli form", Nafdac said in a statement.
The Nigerian customs service, speaking at the same press conference, said that it had acted on "credible intelligence" that "large consignments of plasticized rice were.... to be shipped from the Far East to Africa".
Probably somebody washed the rice in waste water. That would account for the smell and the bacteria.