It began as a seemingly offhand remark by the president of Bolivia, who suggested during a visit to Moscow that he might be happy to host Edward J. Snowden, the fugitive former security contractor who is desperate to find asylum. It escalated into a major diplomatic scramble in which the Bolivian president’s plane was rerouted on Tuesday, apparently because of suspicions that Mr. Snowden was aboard.

By day’s end, outraged Bolivian officials, insisting that Mr. Snowden was not on the plane, were accusing France and Portugal of acting under American pressure to rescind permission for President Evo Morales’s plane to traverse their airspace on the way back to Bolivia. Low on fuel, the plane’s crew won permission to land in Vienna.

“They say it was due to technical issues, but after getting explanations from some authorities we found that there appeared to be some unfounded suspicions that Mr. Snowden was on the plane,” the Bolivian foreign minister, David Choquehuanca, told reporters after the plane touched down in Vienna, where Mr. Morales was spending the night.

“We don’t know who invented this big lie,” the foreign minister said at a news conference in La Paz, Bolivia. “We want to express our displeasure because this has put the president’s life at risk.”