Venezuela has released three Dutch citizens who had been held in prison in the South American country, caretaker foreign minister David van Weel said on Friday.

The three have been handed over to the Dutch embassy in Caracas and are expected to fly home later in the day.

Van Weel said they were the only Dutch nationals known to be detained in Venezuela. Among them are a Dutch captain and his wife, who were arrested last year off the Venezuelan coast as part of an expedition to locate a World War II wreck thought to contain valuable copper.

They and the rest of their international crew were detained by the Venezuelan navy on suspicion of espionage and have been held for seven months.

The identity of the third person released has not been disclosed.

Their release is part of a broader wave of detainees being freed by the Venezuelan regime under pressure from the United States. Alongside the Dutch nationals, prisoners from countries including the Czech Republic, Ireland, Romania and Germany were also released overnight, according to foreign media reports.

Van Weel said he personally lobbied Venezuelan officials on behalf of the Dutch nationals after they were not included in earlier rounds of releases. He welcomed the news as “very good” for their families and for the Netherlands.