Tragic rocker Sonny Bono was clubbed to death by hired hitmen, according to a stunning new tabloid expose. An investigator who has been researching Bono's 1998 fatal skiing accident for the past decade claims top officials linked to an international drug and weapons ring feared the singer-turned-politician was about to expose their criminal acts - and so they had him killed on the slopes. Cher's ex-husband Bono's death was listed as a "skiing accident" with family and friends satisfied he died after colliding with a tree on the piste in Nevada in January 1998. But former FBI agent Ted Gunderson tells America's Globe that there's more to the tragedy than meets the eye, after studying the autopsy reports and other evidence. He says, "It's nonsense for anyone to now try to suggest that Bono died after crashing into a tree. There's zero evidence in this autopsy report... to show such an accident happened. Instead, there's powerful proof he (Bono) was assassinated. "This was an evil plot that was carried out to almost perfection by ruthless assassins." Gunderson tells the Globe Bono, an experienced skiier, was ambushed on the slopes by hired hitmen, who beat him to death and then staged a tree collision. The retired FBI agent is now calling for the authorities to dig up Bono's remains and open a homicide investigation. Gunderson's efforts have been backed by top forensics experts, who fear Nevada authorities were too quick to mark the tragedy as a skiing accident, and investigator Bob Fletcher, who has confessed he sent evidence of a 10-year study that linked top U.S. government officials to arms and weapons dealers to Bono less than a month before his death. Fletcher says, "He was going to make it his number one priority... There's no doubt in my mind Sony was murdered by someone who needed him silenced."