VANCOUVER — Officials believe that a killer whale found dead off Vancouver Island earlier this month died of a bacterial infection caused by a failed pregnancy.

Fisheries and Oceans Canada said preliminary necropsy results show the infection likely originated with the nearly full-term female calf before spreading to its mother.

Pacific marine mammal co-ordinator Paul Cottrell says the calf died at least several days before the mother.

He says it is too early to say whether the orca known as J-32 suffered from long-term starvation, as she likely went into distress after her calf died and didn’t feed for days.

Ken Balcomb, with the Center for Whale Research in Washington state, assisted in the necropsy and says he believes that a lack of a plentiful food source and toxic pollutants contributed to her death.

The whale was a member of an endangered orca population that lives in the waters off B.C. and Washington state.

Only 77 orcas remain in the group and there has not been a successful birth in at least two years.