Four more people have been charged in connection with an alleged cover-up of the rape of a 16-year-old girl by two Steubenville High School footballers.

In a case which attracted worldwide attention, Ma'lik Richmond, and Trenton Mays were convicted of the rape of the 16-year-old girl at a house party in August 2012 when they were aged 16 and 17 respectively.

A grand jury has been investigating whether any other crimes were committed during the investigation into the rape. The original investigation was plagued by accusations of a cover-up in order to protect the small town's high school footballing stars.

Ohio Attorney General Mike DeWine has confirmed four more people - the school's superintendent, a principal, a wrestling coach and a volunteer football coach - have now been indicted in the investigation.

Supt Michael McVey has been charged with tampering with evidence and two counts of obstructing justice. He is also accused of making a false statement and obstructing official business.

The school's volunteer football coach, Matthew Belardine, has been charged with allowing underage drinking, obstructing official business, making a false statement and contributing to the unruliness or delinquency of a child.

Wrestling coach Seth Fluharty and Lynette Gorman, a principal at a Steubenville elementary school, are both accused of failure to report child abuse. All four are due in court on 6 December.

"There is a moral responsibility, and there is a legal responsibility, for people to cooperate with investigators," said DeWine.

"And if you look at the charges in this grand jury, accountability, really , holding people accountable is what I would take away from that. That's what this is about - it's about holding adults accountable.

"How do you hold kids accountable if you don't hold the adults accountable?" he added.

DeWine told reporters that he believed the grand jury's work has finished baring any new evidence.

William Rhinaman, 53, director of technology at Steubenville High School, was charged in October with tampering with evidence, obstructing justice, obstructing official business and perjury in connection with the case.

Photos and videos of the night the rape occurred - including images of the victim being too drunk to stand or talk - were made public by hacktivist group Anonymous, who said more people should have been charged over the rape and help bring the case to a wider attention.

Richmond and Mays were sentenced to one and two years in a juvenile correctional facility respectively.