A Texas man has been charged with cutting a pacemaker out of his dead mother's chest with a kitchen knife as part of a long-running dispute with a medical company. Harris County sheriff's deputies arrested James A. Donalson, 59, on Sunday after paramedics responding to the death of his mother discovered a large incision in her chest, Sergeant Bruce Williams said.

"The son, her caretaker, made the comment, 'I removed the pacemaker,'" Williams said on Monday. "It's my understanding there's been some kind of ongoing dispute between the son, insurance companies and the doctor since this pacemaker was implanted in 1995."

Donalson told reporters he wanted to keep the pacemaker as evidence of possible wrongdoing by its supplier. Investigators also want it to help determine the circumstances of the woman's death.

Donalson was charged with tampering with evidence, a felony punishable by up to 10 years in prison, and jailed in lieu of $5,000 (2,655 pounds) bond.

He was set to appear before a judge on Tuesday morning.

Authorities ordered an autopsy but believe his mother, 85-year-old Ann Donalson, died of natural causes. Her son removed the pacemaker with a kitchen knife at their home just northwest of Houston, police said.

"They killed my mother," Donalson told reporters from the back of a squad car on Sunday, apparently referring to a medical device company.