Passing of Venezuela's Opposition Figure in Custody Called 'Vile' by US Officials.

The United States has criticized the Venezuelan government over the death of a imprisoned opposition figure, describing it as a "reminder of the vile nature" of President Nicolás Maduro's government.

The former governor passed away in his prison cell at the El Helicoide facility in Caracas, where he had been detained for over a year, according to advocacy organizations and opposition groups.

The officials in Venezuela said that the 56-year-old exhibited indicators of a heart attack and was transferred to a hospital, where he passed away on the weekend.

Intensifying Rhetoric Between Washington and Caracas

This latest criticism from the United States is part of an intensifying exchange of rhetoric between the American government and President Maduro, who has accused the US of attempting a change in government.

In the last several months, the US has boosted its military presence in the Latin America and has executed a succession of fatal operations on vessels it says have been used for smuggling narcotics.

US President Donald Trump has claimed Maduro personally of being the leader of one of the region's narco-trafficking organizations—an accusation the Venezuelan president vehemently denies—and has hinted at military action "on the ground".

"Alfredo Díaz had been 'held without cause' in a 'torture centre'," declared the American diplomatic office for the region.

Background of the Detention

He was detained in that year after joining numerous dissidents to dispute the results of that year's presidential election.

Venezuela's pro-government election council declared Maduro the victor, even though counts by rivals suggesting their nominee had won by a wide margin.

The electoral process were largely criticized on the international stage as neither free nor fair, and triggered unrest throughout the country.

The former governor, who led the coastal region, was charged of "stoking division" and "terrorist acts" for challenging Maduro's declaration of success.

Reactions from Rights Groups and the Political Rivals

Local advocacy group Foro Penal has voiced worry over worsening circumstances for detained dissidents in the country.

"Another jailed opponent has died in Venezuelan detention centers. He had been held for a year, in solitary confinement," posted Alfredo Romero, the organisation's director, on a social network.

He added that Díaz had only been granted one visit from his child during the full duration of his incarceration. He added that 17 political prisoners have lost their lives in the nation since that year.

Opposition groups have also criticized the government over the passing of the former governor.

María Corina Machado, a well-known dissident figure who received this period's Nobel Peace Prize but who is in seclusion to escape capture, commented that Díaz's death was not an isolated incident.

"Sadly, it adds to an alarming and heartbreaking sequence of deaths of jailed opponents detained in the aftermath of the post-election repression," she posted.

The Democratic Unitary Platform declared that Díaz "was an unjust death".

Díaz's own political party, Democratic Action (AD), also paid tribute to the former governor, noting he had been wrongly imprisoned without fair treatment and had stayed in situations "that should never have violated his fundamental rights".

Wider International Strains

Tensions between the United States and Venezuela have become ever more tense over what Trump has called efforts to stop the flow of narcotics and immigrants into the US.

• US bombings on ships in the Caribbean and Pacific have killed over eighty people.
• Trump has claimed Maduro of "releasing inmates from his jails and mental institutions" into the US.
• The US has classified two Venezuelan drug cartels as terrorist organisations.

Maduro has conversely claimed the US of using its anti-narcotics campaign as an justification to depose his socialist government and access Venezuela's vast petroleum resources.

The United States has also deployed a large naval force—its largest movement in the region in many years—along with thousands of military personnel.

In a parallel move, the Venezuelan armed forces allegedly swore in more than 5,600 troops in a mass ceremony on Saturday, in answer to what defense officials described as US "threats".