Finding medical professionals willing to advise Ohio on the best way to put condemned inmates to death is proving difficult because of ethical and professional rules, the state's top attorney said.

The rules — which generally prohibit doctors, nurses and others from involvement in capital punishment — are deterring those professionals from speaking publicly or privately about alternatives to the state's lethal injection process, Attorney General Richard Cordray said.

"A small number of promising leads have emerged, but identifying qualified medical personnel willing and able to provide advice to the State regarding lethal injection options continues to be challenging and time-consuming," Cordray said in the Friday filing in U.S. District Court.

Executions are on hold in the Midwestern state while it develops new injection policies following a Sept. 15 execution that was stopped because the inmate had no usable veins.

The state has reached out to judges, police and lawmakers for help trying to find medical professionals willing to talk to the state, according to the filing written on Cordray's behalf by Charles Wille, head of Cordray's death penalty unit.

Cordray also said five lawmakers he didn't identify have agreed to try to find medical staff to help.

The state has a two-year, $33,200 contract with just one doctor, Mark Dershwitz of Massachusetts, a lethal injection expert who frequently testifies on behalf of states in lethal injection cases.

Dershwitz, an expert witness for Ohio at a March trial challenging Ohio's injection system, is the only doctor the state is currently talking to, said Julie Walburn, a prisons department spokeswoman.

Gov. Ted Strickland stopped the execution of Romell Broom after two hours when executioners failed to find a usable vein.

U.S. District Judge Gregory Frost delayed Broom's execution pending a hearing on Broom's request that the state shouldn't be allowed to try to put him to death again.

Strickland, a Democrat, then granted five-month reprieves to inmates scheduled to die this month and next, and Frost delayed a December execution while the state revises its injection policies.

Among the changes the state is considering is injecting lethal drugs into inmates' bone marrow or muscles as an alternative to — or a backup for — the traditional intravenous execution procedure. Broom complained in an affidavit following the execution attempt that execution staff painfully hit muscle and bone at times during up to 18 attempts to reach a vein.

Broom was convicted of kidnapping, raping and killing a 14-year old girl in 1984.

Also Friday, the European Union asked Strickland to spare Broom and temporarily halt all executions in Ohio.