"Heavily armed men dressed in civilian clothes arrived in four vehicles and took him away by force," she said in a post on X.
The former vice-president of the National Assembly is among several political prisoners to have been released since the US captured Venezuela's President Nicolas Maduro in January.
Guanipa was arrested in May 2025, following claims by Interior Minister Diosdado Cabello, made without evidence, that he was involved in an alleged "terror" plot against regional and legislative elections. Guanipa has repeatedly denied the accusation.
Guanipa's son Ramon Guanipa in a video on social media said the kidnapping occurred just before midnight local time, describing it as an ambush in which his father was taken by 10 heavily armed, unidentified men.
"My father has again been kidnapped," he said.
Just hours before, the elder Guanipa had posted several videos to social media after his release from jail in which he spoke to a crowd of journalists and supporters, urging the release of other political prisoners and calling the current administration illegitimate. The US captured and deposed long-time leader Nicolas Maduro in January, leaving his vice president Delcy Rodriguez to take over as interim president.
Venezuela's opposition and human rights groups have said for years the country's socialist government uses detentions to stamp out dissent.
Venezuela's government did not immediately reply to a request for comment about Guanipa's disappearance.
Earlier, Machado celebrated the news of the latest prisoner releases. "My dear Juan Pablo, counting down the minutes until I can hug you! You are a hero and history will always recognise it," she wrote on social media.
Guanipa, a key ally of Machado, was freed after more than eight months in prison along with lawyer Perkins Rocha, was also released but under strict restrictions, according to his wife María Constanza.
