OTTAWA -- Health Canada said Friday it will not release the 300,000 Johnson & Johnson COVID-19 vaccine doses which arrived in Canada in April due to a possible quality issue.

"To protect the health and safety of Canadians in response to concerns regarding a drug substance produced at the Emergent BioSolutions facility in Baltimore Maryland, Health Canada will not be releasing the shipment," the government department said in a statement.

The drug substance produced at the facility was used in the manufacturing of this shipment of Janssen vaccines.

"The drug substance was manufactured at the time a separate batch of vaccines was contaminated by the components of a different vaccine. Health Canada was unable to determine that this shipment of Janssen vaccines meets the Department's rigorous quality standards," said the statement.

To ensure the safety of any future vaccine supply from this facility, Health Canada is planning an onsite inspection, expected to take place this summer.

"Until this inspection has been completed, Canada will not be accepting any product or ingredients made at this site," it said.

The statement came after the US Food and Drug Administration (FDA) said Friday that Johnson & Johnson must throw away millions of doses of its COVID-19 vaccine that were manufactured at the Baltimore facility.

The FDA halted production of the Johnson & Johnson vaccine at the Baltimore site after discovering that ingredients from AstraZeneca's COVID-19 vaccine also being produced at the plant at the time contaminated a batch of Johnson & Johnson vaccine.

An FDA inspection also reportedly found sanitary problems and bad manufacturing practices at the plant.

AstraZeneca's shot is no longer being made at the Baltimore facility, and Health Canada previously said that the 1.5 million doses of AstraZeneca vaccine it had imported from this facility were safe and met quality specifications.