Canadian safety regulators said they "found the problem after reconstructing a fatal crash involving a 2011 RAV4 in Canada."
"The case attracted the department's interest as the front occupants survived the frontal crash, while the rear passengers didn't," Transport Canada said in a statement on Thursday.
The replicated crash used a RAV4 and crash dummies similar in weight to the actual passengers, as well as an impact speed and crash angle that aligned with the fatal crash, it said.
During the test, both rear seatbelts severed and both crash dummies sustained potentially deadly injuries.
"To date, we have received two reports where a crash occurred and a rear seatbelt separated (one from the U.S. and one from Canada)," wrote Nick Maxfield, a Toyota Motor Corp. spokesman, in response to a query from Edmunds. "However, since we cannot confirm the cause-effect relationship between the condition and injuries or fatalities, we are unable to determine whether any injuries or fatalities have been caused by this condition."
Earlier this week, Toyota Motor Sales U.S.A. said it is recalling approximately 1,124,000 2006-'12 Toyota RAV4 SUVs and 2012-'14 Toyota RAV4 EV SUVs in the U.S. to fix a seatbelt problem.
"There is a possibility that, in the event of a very severe frontal crash, the lap belt webbing could contact a portion of the metal seat cushion frame, become cut and separate," Toyota said in a statement. "If this occurs, the seatbelt may not properly restrain the occupant, which could increase the risk of injury."
This is part of a larger global recall of 2.87 million vehicles to address the problem.
Toyota dealers will add resin covers to the metal seat cushion frames of the recalled RAV4s.
Maxfield said owners of the affected vehicles will receive a notification by first-class mail starting in February, alerting them to the recall.
No information about the recall has been posted on the website of the National Highway Traffic Safety Administration, which oversees vehicle safety in the U.S.
Edmunds says: Owners of these vehicles should schedule a service appointment with their dealer once they receive their official recall notice. Those with an immediate concern should contact their dealer now.