COLUMBUS, Ohio (AP) — An Ohio board that oversees attorney conduct said Thursday that attorneys aren't allowed to help someone establish a legal medical marijuana-related business in the state because using, growing, and selling marijuana remains a federal crime.

The state Supreme Court's Board of Professional Conduct also said Ohio attorneys aren't legally permitted to use medical marijuana or to be personally involved in related businesses. Attorneys sought the opinion to determine whether a law barring employers from disciplining professionals from working with marijuana businesses applies to lawyers.

The Ohio Legislature passed a bill in May that allows people with a doctor's prescription to inhale marijuana vapor to treat some chronic illnesses. Gov. John Kasich signed the bill into law, but it's expected to take months before medical marijuana is available to patients.

State Rep. Dan Ramos, a Democrat on the House committee that reviewed Ohio's medical marijuana law, called the advisory opinion "troublesome." He said lawmakers specifically wrote into the legislation that attorneys could practice in this area.

Ramos, of Lorain, said elected representatives passed the law under their constitutional authority, the governor signed it using his powers and it's not up to the professional conduct board to weigh in. "That is deeply troublesome from a constitutional standpoint," Ramos said.

State Rep. Stephen Huffman, a physician and Tipp City Republican who sponsored the legislation, expressed disappointment as well.

"It's going to hamper the ability for the law to be implemented in the spirit of what the General Assembly was trying to accomplish," Huffman said in a statement provided by his office.

Ethics panels in most of the 24 other states that have legalized marijuana have allowed attorney involvement in the marijuana industry. However, Hawaii's disciplinary board issued an opinion last year that said attorneys could give legal advice about the state's medical marijuana law, but couldn't provide legal services to help establish a marijuana business. The panel said that would be considered assisting a federal crime.