A condemned Ohio man asked a federal judge Thursday for an emergency order to stop next week's planned execution, arguing the state is rushing too fast to use its new, one-drug lethal injection process.

Kenneth Biros said the untested method announced last month could jeopardize his right to an execution that does not constitute cruel and unusual punishment.

Biros, 51, says moving ahead with the process would amount to human experimentation with a system never used before in the United States "or any other civilized country."

Biros is concerned the method "will not result in the dignified, humane, quick, and painless death that is required by the federal and state constitutions," his attorneys said in Thursday's court filing.

Biros has also challenged the one-drug method in federal court and also asked a federal appeals court in Cincinnati to delay Tuesday's execution.

Biros killed 22-year-old Tami Engstrom near Warren in 1991 after he offered to drive her home from a bar, then scattered her body parts in Ohio and Pennsylvania.

The state opposes any delay, and Gov. Ted Strickland on Thursday denied Biros' request for clemency.