A woman accused of helping her stepbrother and alleged lover clean up after the sadistic murder of their parents has been released.

Karen Klein, 22, was set free after her lawyers in Argentina argued she had acted under pressure from her co-accused, Leandro Yamil Acosta, 25.

They said she had helped him clean up after he shot his stepfather in the head, then killed his mother with another three bullets when she returned a few hours later from taking his twin stepbrothers aged 11 to school.

He admitted the killings and also said he had eaten part of his dadís body and had sex with the coupleís corpses. He then cut up the remains and burnt them before feeding what was left to the familyís six dogs.