Lopez, 46, a U.S.-educated economist and leader of the Popular Will party, is beloved by some in the opposition who admire his hardline stance and see him as a future president.
The opposition leader had been sentenced to almost 14 years in prison in 2015 but was sent home amid massive protests.
The government released a video of the 46-year-old as a "proof of life", but his wife, Lilian Tintori called it fake.
The Harvard-educated Lopez was jailed for allegedly sparking anti-government protests that ended in violence.
Armed assailants in a vehicle shot Luis Diaz, head of Democratic Action party in Altagracia de Orituco