The Star-Ledger (http://bit.ly/NT6nis) reports the tests - which involved administering high doses of vitamin D and calcium - were apparently conducted without the consent of the residents' families.
State health officials told the newspaper that the doctor and nurse practitioner were put on paid leave in December, and an internal investigation into "questionable medical standards of care and circumventing an approved process for research" is ongoing.
The matter also was referred the matter to the state Division of Criminal Justice, which declined comment.
No charges have been filed in the matter.
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