A black garbage bag containing an infant sleeper lies in the backyard of a house in London, Ont., where the remains of three infants were found over the weekend. (Karen Elliott/Canadian Press)

A 32-year-old woman in London, Ont., was arrested again on fresh charges Tuesday after an autopsy determined the remains of three babies — not one, as originally suspected — were found in a home on the weekend.

Police were called to the home in the city's northeast on Saturday after the current resident found remains of what was believed to be an infant in advanced stages of decomposition in a bucket in the basement.

An autopsy performed on Monday determined the bucket contained the remains of three infants, London police said.

The house was being rented by a woman and her boyfriend, but the couple recently split up, and the woman moved out, the CBC's John Lancaster reported on Tuesday from outside the house.

According to a neighbour, the ex-boyfriend came out of the house on Saturday with a bucket that contained blood-soaked baby clothes.

"He came outside and told everybody he discovered this bucket," the neighbour told CBC News. "He said his girlfriend had this bucket for two years with gardening stuff in it, and he opened it on Saturday, and it was [filled with] bloody clothes and a blanket, and he called the police."

"Within minutes, we had lots of police and [in] a few more minutes, lots of detectives, forensic vehicles. It was pretty scary."

A forensic identification van is parked outside the London home where police are investigating the discovery of infants' remains. (CBC)

"The look on the man's face when he came through the front door holding the bucket was unbelievable," the neighbour told Lancaster.

Jennifer Sinn, 32, was initially arrested on Saturday and then released after being charged with concealing the body of a child and offering an indignity to a dead human body.

Sinn faces two additional counts of each charge and is again in police custody, London Police Service spokeswoman Const. Amy Phillipo said Tuesday.

Sinn is described by police as a former occupant of the home.

Neighbours said she had a one-year-old girl whom they said they hadn't seen in weeks.

The remains will be sent to the provincial forensic pathology unit in Toronto for further investigation.

Forensic investigators have not yet determined the gender, the exact ages or the cause of death of the three infants.

With files from The Canadian Press