INDIANAPOLIS -- Court documents say a retired Indianapolis fertility doctor used his own sperm to impregnate several women decades ago and admitted to six now-adult children to doing so.

Dr. Donald Cline pleaded not guilty to Monday to two felony obstruction of justice charges for misleading authorities who were investigating two of the children's complaints against him.

A probable cause affidavit says the 77-year-old suburban Zionsville man told the six adults that he had donated his own sperm about 50 times. His patients were told they were receiving sperm from medical residents or students.

Cline is accused of being the biological father of at least eight people. The youngest would be about 30.

Cline's attorney says he's not accused of not co-operating with authorities.

He was released on his own recognizance.