The lawyer of Venezuelan opposition leader María Corina Machado has been detained.
Perkins Rocha also serves as legal adviser for the opposition Vente Venezuela party.
He is the latest person with links to the opposition to be seized in the aftermath of last month’s presidential election.
The government of President Nicolás Maduro has detained more than 2,400 people over the past month, creating what the UN has called “a climate of fear”.
Vente Venezuela said unidentified men had seized Mr Rocha by force and his whereabouts where unknown.
Rights group Provea has warned that political persecution in Venezuela has been intensifying since 29 July – the day that the government-controlled National Electoral Council (CNE) declared President Maduro the election winner.
While the CNE said that Mr Maduro had won a third consecutive term in office with 52% of the votes, it failed to provide detailed tallies from the polling stations to back up its announcement.
The opposition has disputed the CNE’s result, saying that copies of voting tallies it gathered on election night show that its candidate, Edmundo González, won 67% of the vote, compared to Mr Maduro’s 30%.
It has uploaded copies of the tallies to the internet, which have been reviewed by the Washington Post and the Associated Press news agency.
Both the Washington Post and AP reviewed scans of more than 23,000 tallies – a sample which represents nearly 80% of the total – and found that they showed that Mr González had an advantage of more than 3.7 million votes over Mr Maduro.
Mr Maduro responded by taking the matter to the Supreme Court.
The court, which is stacked with Maduro loyalists, last week upheld the CNE’s decision to hand Mr Maduro a third consecutive term in office.
The court’s decision was read out by the head of the Supreme Court, who is an active member of the governing party.
The UN Human Rights Council has questioned the court’s impartiality and independence, accusing both the court and the CNE of playing a role in the state’s repressive machinery.
Venezuela’s opposition coalition has called for renewed protests on Wednesday to demand once again the publication of the voting tallies.
But there are fears these protests could be met with increased repression by the security forces after the nomination on Tuesday of hardliner Diosdado Cabello as minister for the interior, justice and peace.
In his new role, Mr Cabello will be in charge of Venezuela’s feared secret police, as well as the National Guard.
Mr Cabello has often vowed that opposition to the government be met with an iron fist. He has said in the past that he thinks Edmundo González and María Corina Machado should be “behind bars”.
The two opposition leaders have been in hiding in the past weeks, with Ms Machado only emerging sporadically to address her supporters at protest rallies.
On Monday, Ms Machado said they would “not rest” and urged her supporters to keep up the pressure.
