Venezuelan authorities released American journalist Cody Weddle on Wednesday evening following his arrest in the morning, Miami television station WPLG Local 10 reported.
WPLG, one of the outlets for which Weddle worked, added that he was at the main Caracas-area airport waiting for a US-bound flight. It did not cite its sources on his release but said his mother was “relieved” to learn the news.
In the latest crackdown on a challenge to his rule by opposition leader Juan Guaido, President Nicolas Maduro also expelled the German ambassador, accusing him of repeated meddling in the country's affairs.
On Monday, Ambassador Daniel Kriener and diplomats from other embassies had welcomed Guaido home at the Caracas airport.
Guaido had flouted a court-imposed travel ban to visit other Latin American countries to drum up support.
Most Western countries, including Germany, have recognised Guaido as the OPEC nation's legitimate head of state and back his plan to install a transitional government ahead of free elections. Guaido says Maduro's re-election last year resulted from a sham vote and blames him for an economic collapse that has led to widespread shortages and hyperinflation.
The United States slapped sanctions on Venezuela's vital oil industry in January to try to cut off government revenue and force Maduro out and pledged further action on Wednesday. A senior official in the administration of US President Donald Trump said it had identified efforts by Maduro to work with foreign banks to move and hide money.
"We will be sanctioning some in the days and weeks to come," the official said, hours after National Security Advisor John Bolton warned foreign banks that they could face sanctions if they participated in transactions benefiting Maduro.
The United States will also revoke the visas of 77 people associated with Maduro, US Vice President Mike Pence said, adding to a list of 49 others whose visas were revoked last Friday.
Despite the pressure, Maduro - a socialist who says he is the victim of an attempted coup and "economic war" led by the United States - retains control of state functions and the support of the armed forces.
Maduro has continued to defy the Trump administration. Venezuelan military counterintelligence agents detained American journalist Cody Weddle and his Venezuelan colleague Carlos Camacho early on Wednesday, Venezuela's National Press Workers Union said on Twitter.
Camacho was released in the evening after 12 hours in custody, the union said, adding that Weddle remained in custody.
Freelance Caracas-based reporter Weddle, who recently covered Guaido's return to the country for Miami television station WPLG Local 10 News, was arrested at his home on charges of treachery, according to free speech group Espacio Publico. Agents took Weddle's computer and equipment, the group said.
"We demand the liberation of the American journalist Cody Weddle, who was kidnapped by a regime that usurps its functions and tries, without success, to hide the truth of what is happening in our country," Guaido wrote on Twitter.
Venezuela's Information Ministry did not respond to a request for comment.
The move, which came a week after Venezuela deported a team from U.S. television network Univision, drew condemnation from Organization of American States Secretary-General Luis Almagro and several U.S. lawmakers from both major parties.
"We have been informed of the detainment of Cody Weddle by his family, and I urge his swift and safe release by Venezuelan authorities," Mark Warner, a Democratic senator from Weddle's home state of Virginia, wrote on Twitter.
Kimberly Breier, the top U.S. diplomat for the Western Hemisphere, said on Twitter that the State Department was "aware of and deeply concerned with reports that another U.S. journalist has been detained in Venezuela," without naming Weddle.
WPLG reported on its website that its management's attempts to reach Weddle "have proven unsuccessful" and that his last contact with station employees was on Tuesday afternoon.
The arrest threatened to worsen already-fraught relations between Venezuela and the United States, which has reduced its diplomatic presence in the country after Maduro in January said he would break ties. Maduro has also ended relations with neighbouring Colombia.
While most major European countries have backed Guaido, relations have not deteriorated to the same extent, with the European Union supporting dialogue with Maduro to negotiate the terms of new elections, an approach that has been criticized by the United States and parts of the domestic opposition.
The expulsion of Kriener, however, will likely deepen the divide between Maduro's administration and Europe. The government gave him 48 hours to leave the country but did not provide specific details on why he was being expelled.
"Venezuela considers it unacceptable that a foreign diplomat carries out in its territory a public role closer to that of a political leader aligned with the conspiratorial agenda of extremist sectors of the Venezuelan opposition," it said in a statement.German Foreign Minister Heiko Maas called the move "an incomprehensible decision, which escalates the situation instead of easing tensions." European support for Guaido was "unwavering," he added.