1989 Chilean grape scare
The Chilean grape scare was a 1989 incident involving two grapes from Chile allegedly found tainted with cyanide after a threat was supposedly made by phone to the US Embassy in Santiago. No additional contaminated fruit was found, but the United States Food and Drug Administration banned the import of Chilean fruit and warned people not to eat grapes or Chilean fruit despite the fact investigators found no traces of cyanide in any other fruit shipped from Chile to Philadelphia.
The scare
The individual who supposedly telephoned the U.S. embassy in Santiago on March 2 told them some Chilean grapes contained cyanide. No individual or group ever claimed responsibility for poisoning the two grapes or making the phone call. Just two grapes were said to have been injected with cyanide and the country's fruit export sector was thrown into panic. Thousands of farm workers lost their jobs and the Government was forced to provide temporary subsidies to offset the more than $400 million in losses.
The doubts
Because cyanide is highly reactive and the fact that a punctured grape decomposes rapidly, it is not possible for a grape to be injected with cyanide (or anything else for that matter) and arrive in the U.S. intact, two to three weeks later. This fact led the GAO (General Accounting Office) to investigate to determine whether the scare was a result of poor laboratory processes. The investigation was inconclusive.