ASUNCION - A controversial presidential candidate who helped topple Paraguayan dictator Alfredo Stroessner in 1989 has died in a helicopter crash, officials said Sunday, prompting claims of foul play.
Lino Oviedo, 69, died with his bodyguard and pilot when the aircraft crashed en route to Asuncion while they were returning late Saturday from a campaign rally in northern Paraguay, the officials said.
The cause of the crash was not immediately known, though early indications suggest the helicopter was caught up in a storm before it plummeted and hit the ground at a cattle ranch.
"At this point, all hypotheses are open," said civil aviation director Carlos Fugarazzo, noting that foreign experts would be called in to investigate the crash.
Oviedo was a former head of the Paraguayan military. His death was confirmed to AFP by Senator Herminio Chena, who is close to Oviedo's family.
"It's hard for us to accept it. We cannot believe it," Chena told AFP, choking back tears.
But there were immediate claims that the crash was not an accident. Diego Galeano, the brother of Oviedo's bodyguard Denis Galeano, told AFP "there is a strong suspicion that the helicopter was shot at," but he gave no proof.
Oviedo, who was running for the conservative UNACE party, was one of the three top candidates in the April 21 presidential election. In 2008 he ran for president and came in third, with 22 percent of the vote.
Oviedo, who came from humble origins, rose to fame when Stroessner -- Paraguay's dictator for 35 years -- surrendered to him in a 1989 military coup. Oviedo died 24 years to the day since that event.
Oviedo fled to Paraguay in 1996 when then-president Juan Carlos Wasmosy accused him of orchestrating a failed coup.
He was court martialed and sentenced to 10 years in jail, and was later indicted for masterminding the murder of vice president Luis Maria Argana in 1999.
After years of hiding in Argentina and Brazil Oviedo returned to Paraguay in 2004, spent time in prison, and after legal wrangling had his rights fully restored by the Supreme Court.
Paraguay's upcoming election comes after its senate in June ousted the president, leftist former Catholic bishop Fernando Lugo.
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