The police officer facing murder charges over the shooting death of an unarmed black man, has also been charged with violating the man’s civil rights and misleading investigators.

Michael Slager was charged with murder over the shooting death of Walter Scott in North Charleston, South Carolina, last spring. Mr Slager was captured on cell phone footage shooting at Mr Scott as he ran away from the officer, and with his back turned.

The Post and Courier newspaper reported that a grand jury, organised by prosectors, had indicted the officer with three additional charges.

The newspaper said that the extra charges could help prosecutors if they failed to convict the 34-year-old former officer on murder charges. Putting him on trial in both state and federal courts for the same shooting would not be double jeopardy because the alleged crimes are different.

Mr Slager is due to be formally charged on Wednesday in Charleston.

The killing of Mr Scott came during a period when police forces across the country were under close scrutiny after a series of incidents in which black or minority suspects were killed or injured.

The newspaper said that the grand jury, which first met nearly a month ago, handed down the indictment on Tuesday. Officials did not make it public until Wednesday, when they made the case one of the few high-profile American police killings in recent years to result in a federal criminal charge.

Mr Slager has insisted that his actions were justified. He is currently on bail.

The family of Mr Scott, is expected to speak to the media on Wednesday after the additional charges are formally brought.

A spokesperson for the Scott family, Ryan Julison, says that “neither the relatives nor the attorneys would discuss until then what the proceeding would be about”.

Last year, North Charleston authorities approved a $6.5m civil settlement with Mr Scott’s family.

The settlement gives annuities totaling $1m to three of Walter Scott's four children. Mr Scott’s estate will get $3m, while three law firms who helped represent his family will divide about $2.4m.