A conservative candidate in Paraguayan presidential elections scheduled for April has died in a helicopter crash, the government said Sunday. Lino Cesar Oviedo, his bodyguard and their pilot died in the crash Saturday night after taking part in a campaign rally and flying back to the capital Asuncion. Oviedo, 69, was the candidate of a conservative party called Unace. He is a former army chief who got into politics in 1996. Civil aviation director Carlos Fugarazzo announced a probe that a probe has been launched and said international experts would be called in. "At this point, all hypotheses are open" as to what might have caused the crash, he told a news conference. The election is scheduled for April 21. Oviedo's party is among around a dozen in the running. Unace is a splinter group that broke away from the Colorado Party. Oviedo's death was first confirmed to AFP by Senator Herminio Chena, who is close to Oviedo's family. The chopper went down in a rural area. When long-time dictator Alfredo Stroessner surrendered in a 1989 military coup, it was Oviedo who took custody of him in a bunker. Oviedo died 24 years to the day since that event.