Marcus Stanford has pleaded guilty to being an accessory to the murder of NSW schoolteacher Stephanie Scott.

Stanford is the twin brother of Vincent Stanford, who is accused of raping and murdering Ms Scott, 26, last year.

She was last seen on April 5, Easter Sunday, just days before her wedding.

• Scott accused fronts court
• Stephanie Scott murder: Twin brother arrested

Her burnt body was found in the Cocoparra National Park, about 70km from the town of Leeton, where she worked as a teacher at Leeton High School.

Vincent Stanford, a 25-year-old cleaner at Leeton High School, was arrested four days after her disappearance.

He was charged with sexually assaulting and murdering Ms Scott.

His twin, Marcus Stanford, was arrested in June last year and charged with being an accessory after the fact.

He was extradited from his home in ForrestonSouth Australia to NSW at the time.

Vincent and Marcus Stanford are appearing today in Griffith Local Court.

Marcus Stanford is expected to be sentenced in May.

Marcus Stanford pleaded guilty to being an accessory after the fact. Photo: ABC