Your trusted source

The dark claim on the day Hugo Chavez died took many by surprise, CNN reported.

Someone, Venezuelan government officials said, may have deliberately infected him with cancer.

Critics dismissed the accusation -- first floated by then-Vice President Nicolas Maduro on March 5 -- as an eleventh-hour attempt to distract Venezuelans and drum up popular support as leaders prepared to announce Chavez's death.

But Maduro revived the issue this week, announcing that planning was in the works for a commission of "the world's best scientists" to investigate whether Chavez had been poisoned.

In an interview with the Telesur network hours after he registered to run for president Monday, Maduro implied that the United States could have been behind such an attack on Chavez -- an accusation that the State Department has denied.

"We have this intuition that our commander Chavez was poisoned by dark forces that wanted to be rid of him," said Maduro, who was sworn in as Venezuela's interim president on Friday.

In the 1940s and 1950s, the United States and other countries had "scientific laboratories testing how to cause cancer," Maduro said. "Seventy years have passed. These kinds of laboratories of evil and death have not advanced?"

Maduro stressed that he was not accusing the United States.

"I am just saying something that is a truth, that is known," he said.

But his recent comments have drawn sharp responses from the U.S. government.