A Montreal family has been charged in the deaths of their three teenage daughters and a 52-year-old caregiver, more than three weeks after police pulled four bodies from a car submerged near Kingston, Ont.

According to Kingston police Chief Stephen Tanner, the deaths are a "needless and senseless loss of innocent human lives," and could be an extreme case of domestic violence.

The girls' father, mother and brother all face four counts of first-degree murder each. The four bodies were discovered on June 30 in the Rideau Canal.

The victims are 19-year-old Zainab Shafia and her sisters Sahar, 17, and Geeti, 13. The fourth victim is Rona Amir Mohammad , who was revealed to be Shafia's first wife. She was previously described as a cousin.

Police allege that the parents and their son all operated the car which was dumped in the canal, and that the father lied when he told police the deaths occurred by accident during a family vacation.

Three weeks ago, the girls' father Mohammed Shafia told police that the family was driving home from a vacation in Niagara Falls in two cars.

But after the family had stopped in Kingston for a night, the car carrying the girls went missing, Shafia said at the time.

Shafia reported the car missing to police and said that the eldest girl had been known to take the car out without permission.

Autopsy results haven't been released.

The family is originally from Afghanistan but moved to Canada after spending 15 years in Dubai. Police say the family's culture may have contributed to the deaths.

"All shared the rights within our great country to live without fear, to enjoy safety and freedom ... and yet had their lives cut short by members of their own family," said Tanner.

He also asked for a moment of silence for the victims.

Mohammad Shafia, wife Tooba, Yahya Shafia and their son Hamed Mohammad-Shafia, 18, all face four counts each of murder and conspiracy to commit murder.

Early on, the deaths appeared to puzzle investigators as they pieced together how the Nissan had plunged into the water. There was speculation that the deaths were the result of careless driving or had occurred after the car's driver lost control.

However, there were several barriers between the roadway and the water, and police couldn't find significant tire marks which would have been consistent with a case of reckless driving.

After the car was discovered, the remaining family members shared their grief with the media and openly discussed their loss.

Meanwhile, officers continue to investigate an email sent to police which suggests the deaths were the result of a so-called "honour killing."

Tanner said the email may have come from a family member. However, that has not been confirmed, and the allegations contained in the email have not been proven in court.

"That person is far removed from Canadian soil and from direct knowledge so we have to, and will, investigate that fully in coming weeks," he said.

News organizations also received an email, purportedly from a relative, that alleges Rona -- Shafia's first wife -- feared for her life and was regularly threatened by her husband.

The email also states that Shafia thought Western culture was negatively influencing his family, and alleges that "the daughters were beaten regularly, either by him or his son Hamed, because their behaviour was a disgrace to him in his eyes," The Canadian Press reported.

The accused appeared in a Kingston court Thursday, but did not enter a plea. A bail hearing is pending.

Defence lawyer Lucie Joncas, who is representing the mother, said her client is deeply saddened by the deaths.

"It's obvious my client is very emotionally distraught by the whole tragedy,"

With a report from CTV's Rosemary Thompson