Police investigators bring evidence bags from a house in London, Ont., on June 9, where the remains of three infants were found in the basement last weekend. (Dave Chidley/Canadian Press)

Police say the three babies whose badly decomposed remains were discovered at a home in London, Ont., may not have been carried to full term, and the investigation will likely take many more months.

"If they weren't full-term they were near-to-full-term," police Chief Murray Faulkner said at a news conference at London police headquarters Monday morning.

He added: " There may be more questions unanswered than answered today."

"Some of the important questions [in this case] will be answered by the Centre for Forensic Science [in Toronto]," Faulkner said.

Police were called to a residence in London on June 6, where they discovered what was believed to be the decomposing remains of one infant in a box.

An investigation revealed the remains of two more infants, but autopsies failed to confirm positively the causes of death.

Jennifer Sinn, 32, has been arrested and charged with three counts each of causing an indignity to a body and disposing of a child's body with intent to conceal delivery.

Faulkner said the autopsy has determined that the bodies were disposed of between December 2001 and June 2009.

The autopsy did not determine the gender or parentage of the infants, though police say they expect forensic examinations to turn up more information in the coming months.

"We have been advised that it will probably take months to do a determination on those two specific items [gender and parentage]," the chief told reporters.

Faulkner said the police haven't made a decision yet on whether homicide charges are warranted. He would only say that the investigation is "ongoing."

Sinn spent most of her life in Brampton but moved to southwestern Ontario in March 2008. Police believe the box containing the remains of at least some of the infants made the move with her.

"The box made it from Brampton to London," said Faulkner.

Sinn, who police say is exercising her right to remain silent and not co-operating in their investigation, is in custody and will make her next court appearance on Friday.

With files from The Canadian Press