police discovered the body of a female at a national park on friday .
it is believed to be the remains of teacher stephanie scott , 26 .
the body had been burnt and a gasoline can was found nearby .
vincent stanford , a cleaner at her school , has been charged with murder .
stanford 's family led police to cocoparra national park north of griffith .
forensic testing will be carried out on the remains of the body .
ms scott was due to marry her partner aaron leeson-woolley on saturday .