Twin arrested in Steph Scott murder probe

The twin brother of teacher Stephanie Scott's accused killer has been arrested in South Australia, accused of playing a part after the alleged murder.

Marcus Stanford, 24, was arrested at a Forreston property in the Adelaide Hills early on Tuesday morning by NSW and South Australian detectives.

He will face Mount Barker Magistrates Court on Wednesday and detectives will apply for his extradition to NSW.

He is expected to be charged with being an accessory after the fact to the murder of Ms Scott in the NSW Riverina town of Leeton in April.

His twin brother, Vincent, is already in custody, accused of sexually assaulting and murdering the 26-year-old on April 5.

Ms Scott, an english and drama teacher, was last seen at her workplace Leeton High School on that day, when she was getting her work in order ahead of her honeymoon.

She died six days before she was due to marry her fiance Aaron Leeson-Woolley at a country wedding in Eugowra.

Three days after she disappeared, police visited the Leeton house where Vincent Stanford lived with his other brother and mother.

Officers found a camera with photographs of a burned body on it and blood, allegedly in the back of Vincent Stanford's ute.

After days of searching, police on dirt bikes found Ms Scott's burned remains dumped off an isolated dirt road in Cocoparra National Park on April 10.

It is believed Vincent Stanford moved to Leeton about 13 months before he was arrested.

He was employed as a casual cleaner for an Albury-based company and often worked at Ms Scott's school.

Twin brother Marcus lived in South Australia.

The siblings spent the majority of their childhood in Holland, where their mother is from.

Last week, police charged Vincent Stanford with the aggravated sexual assault of Ms Scott.

He is due to face Griffith Local Court via audio visual link in September.