The Organization of American States has declared Venezuela's recent gubernatorial elections to be illegitimate, citing a series of irregularities including the lack of independent poll observers.
The opposition Democratic Union Roundtable (MUD) coalition was routed in the October 15 vote by President Nicolas Maduro's socialists, who won in 18 of Venezuela's 23 states.
The opposition had portrayed the vote as a referendum on the unpopular Maduro after months of deadly street protests earlier this year failed to unseat him.
The election lacked "numerous guarantees for the results to be recognized as legitimate," said the 11-page OAS report posted in Spanish on the group's website on Tuesday.
The OAS document noted among other things the "systematic" violation of constitutional rights and the difficulties the opposition had to compete on an equal footing with pro-government candidates.
Pro-government candidates won handily despite pre-vote opinion polls that showed the opposition ahead in as many as 18 Venezuelan states.
The vote "was clearly plagued with irregularities that restricted the political rights of citizens," so the results published by the National Election Council did not reflect "the will of the Venezuelan people."
The election underscores the importance of impartial international election observers, the OAS said.
A high abstention rate among voters compared to the 2015 mid-term election turnout contributed to the opposition defeat.
The United States -- which has imposed sanctions on Maduro and his inner circle over what it calls Venezuela's slide into dictatorship -- on Monday said the lack of outside observers, last-minute changes to polling station locations and other irregularities meant that the Venezuela vote was not credible.