A federal judge has delayed a religious cult leader's execution to allow him to join a lawsuit challenging Ohio's use of lethal injection.

Jeffrey Lundgren, 56, was scheduled to die on Oct. 24 for killing a family of five in 1989.

He asked for a postponement to join the lawsuit, saying he is at even greater risk of experiencing pain and suffering during injection than other inmates because he is overweight and diabetic.

Five death row inmates argue in a lawsuit filed in 2004 that the way the chemicals are administered makes the process painful enough to amount to cruel and unusual punishment, a violation of the U.S. Constitution.

In granting Lundgren's request on Tuesday, U.S. District Judge Gregory Frost said there was no need for a long delay. He said it appears that potential flaws with Ohio's execution process could be fixed easily.

"Thus, any delay in carrying out Lundgren's execution should and can be minimal," Frost said.

Ohio Attorney General Jim Petro will appeal Frost's ruling, said spokesman Mark Anthony.

Lundgren was convicted of shooting Dennis and Cheryl Avery and their three daughters while they stood in a pit dug inside his barn in northeast Ohio.

Lundgren formed a cult after he was dismissed in 1987 as a lay minister of the Reorganized Church of Jesus Christ of Latter Day Saints, now known as the Community of Christ. Several people had moved with him to a rented farm house 23 miles east of Cleveland, where they called him "Dad" and contributed money for group expenses.

The Averys had moved from Missouri in 1987 to follow Lundgren's teachings. Lundgren said passages in the Bible told him to kill the family.

Ohio's method of lethal injection came under national scrutiny by death penalty opponents in May after problems slowed the execution of Joseph Clark. The execution team had trouble finding a suitable vein in the arms of Clark, a former intravenous drug user, and the vein they chose collapsed as the chemicals started flowing.