A seven-month-old baby died after doctors at a hospital in the US flushed his system with alcohol instead of saline solution during a heart surgery.

The incident, termed as a terrible mistake, occurred while Tressel Meinardi underwent heart surgery at the Cincinnati Children's Hospital Medical Center in Ohio Aug 21, the Herald Sun reported Friday citing cincinnati.com.

The injection of alcohol caused organ failure in the baby, a resident of Richmond in Indiana state.

'There's no question a mistake was made,' Coroner O'dell Owens said.

Police are now investigating how the mistake occurred.