LONDON, Ont. - The decomposed remains of three infants that police allege had been stored in a tote box by their mother for years went under the forensic microscope Thursday in the hopes of uncovering the causes of death.

Police in London, Ont., where the remains were found in a home, believe the babies died in the years 2001, 2002 and 2006, court documents show.

Jennifer Sinn, 32, faces three charges of causing an indignity to a body and three of disposing of a child's body with intent to "conceal the fact that its mother, namely Jennifer Sinn, has been delivered of it," the documents read.

The autopsies at Ontario's Center of Forensic Sciences began Thursday and were ongoing, said London police spokeswoman Const. Amy Phillipo.

Investigators had not received any test results back from the lab, she added.

Sinn had lived in the home where the remains were found for about six months, and London police were working with Peel Region police and the provincial force to track the woman's movements over the years.

Sinn had previously lived in Brampton, Ont., among other cities across the province, police have said.

The remains were so badly decomposed that police initially believed they were investigating the death of one child.

Sinn had initially been released from custody on a promise to appear in court, but was re-arrested Monday when a medical examination revealed there were three infants involved.

Sinn briefly appeared in court Tuesday and is being held in custody until her next court appearance, scheduled for June 19.