CHICAGO (AP) _ Eight horse owners, trainers and competitors have been charged in the latest wave of a federal investigation into valuable horses being killed for insurance money, authorities said Thursday.

In one case, a rider and trainer warmed up baseball-style with a crowbar, then smashed a horse's leg in order to collect the insurance, said U.S. Attorney James Burns.

``We will not tolerate the savage killing of these beautiful animals and this type of insurance fraud,'' Burns said.

Thirty-six people have been charged in the fraud probe. Of 23 originally charged in the summer of 1994, 22 have been convicted or pleaded guilty. The government's investigation began as a probe into the disappearance of candy heiress Helen Vorhees Brach.

While investigating Brach's boyfriend, horse trader Richard Bailey, they received a tip that Burns was about to kill a show horse for insurance money.

Among those charged Thursday with fraud and lying to authorities was horse owner James Heinsohn of Glenview, Ill., accused of lying to the FBI about the death of his horse, Pet of the Year. The horse, jerking back after drinking from an electrified water trough, fell and broke its back and had to be killed, Burns said. The horse's killer, Ronald Mueller, earlier admitted destroying that horse for insurance money with Heinsohn's approval.

Trainer Wally Holly and an equestrian competitor, Freddie Vasquez Jr. were accused of killing Vasquez's horse with a crowbar, then collecting a $15,000 insurance premium on the horse.