The security chief of Venezuelan opposition leader Maria Corina Machado was arrested early on Wednesday, her Vente Venezuela political movement said on X, raising questions over whether the July presidential election will be fair and free.

The arrest comes less than two weeks before the July 28 vote, where the opposition coalition's candidate Edmundo Gonzalez is polling significantly ahead of President Nicolas Maduro, who is seeking a third term.

Machado was barred by a court from running in the election over alleged fraud violations, which she denies, forcing her coalition to rally behind Gonzalez, a former diplomat. Several dozens of Machado's allies have also been detained, opens new tab.

The Vente Venezuela movement said officials took Machado's security chief, Milciades Avila, from the house where he had been staying.

"I'm warning the world about Maduro's escalation of repression against those who work in the campaign or help us in any part of the country," Machado said via X.

Venezuela's opposition has repeatedly denounced arrests and other moves by the authorities that they say are meant to harm its election campaign and prevent a fair election.

Avila was "accused of gender violence" against a group of women who had "tried to attack Edmundo and me" in a food store in Valencia last Saturday, she said.

Pictures in local media showed a group of women, including some officials from a regional governor's office and known supporters of the ruling party, confronting Machado and Gonzalez.

Machado claimed on X that detaining Avila was aimed at leaving her team unprotected for the remaining period of the election campaign.

Avila has worked with Machado for a decade and "risked his life to defend me", she said.

Machado said she held Maduro responsible for Avila's safety and that of 24 other team members who have been detained.

Foro Penal, a non-governmental organization, said on Monday that 102 people have been detained since the start of the election campaign on July 4.

The Venezuela Ministry of Communication and the Attorney General's Office did not immediately respond to requests for comment.

The United States and others have dismissed the 2018 re-election of Maduro, a Socialist, as a sham. Washington has urged Maduro's government to ensure the election is "competitive and inclusive".

Six of Machado's former campaign staff are currently seeking political asylum at the embassy of Argentina.