Mr. Gautier said the rats had moved from the trailers into the elections commission offices.

A spokeswoman for the elections commission said the offices were being used as a storage point at the request of Puerto Rico’s first lady, Beatriz Rosselló, who founded a group that served as an umbrella for donations, United for Puerto Rico. The spokeswoman said the donated material was being managed by the National Guard.

United for Puerto Rico said it had no knowledge of the containers and had nothing to do with them. In a statement, the National Guard said the container captured on video was being used to hold food that had arrived after its expiration date, and had not been held back from distribution in order to protect peoples’ health. However, the video also showed cases of water, which was also in short supply at times after the storm.

The Guard said that the material in the trailers that isn’t spoiled, including batteries, electric fans and food, will be distributed to nonprofit groups in the coming days. It did not explain why the material had not been handed out earlier.

The New York Times viewed the containers on Friday, two days after Radio Isla shot the video, but by then, they had been padlocked.

“The containers have been there for a long time, but they weren’t necessarily filled at all times,” Major Dahlen said. “The good thing is now that thanks to investigative journalism, it will help move along the process and get it where it needs to go in the coming days.”

It is unclear how many trailers had been at the site throughout the year. On Wednesday, the radio station saw nine trailers, plus a 10th that was being removed by the Department of Corrections.

It was not the first time food donated for Puerto Rico’s hurricane victims has gone to waste. Tons of supplies collected and sent by a South Florida man went bad when it turned out that he had paid the charter flight companies with fake checks. The airlines put a lien on the materials, which got soaked and ruined in the damaged airport.

On Thursday the man who organized the drive, Emilio I. Vazquez, 47, of Coral Gables, Fla., was ordered to pay $1.5 million restitution and sentenced to 120 months in prison.