Police in Vancouver have recovered all 19 vials of HIV-positive blood stolen from a hospital in the city's downtown more than a week ago.

Police spokesman Const. Tim Fanning said 18 of the vials showed up Friday in a drop box for used syringes at an undisclosed downtown medical facility.

The other was discovered Sunday by a security guard on the grounds of St. Paul's Hospital, where the vials had been stolen.

Police said none of the vials appear to have been tampered with.

Fanning said it seems the thief took the vials from a locked freezer without realizing what they contained, and then disposed of them in the safest way possible after realizing they had no cash value.

He added these kinds of crimes happen quite often, noting that thieves will steal anything that has been locked away and then decide whether it has any value.

Each vial was labelled with a patient's name and marked with the lettering "HIV VL."

The hospital says it's increased security for HIV-blood samples such as the stolen ones, which were to be used for research.

St. Paul's is home to researchers with the B.C. Centre for Excellence in HIV/AIDS.

Police say their investigation is continuing.