A longtime doctor and nurse practitioner at a New Jersey-run residential center for the developmentally disabled are under investigation for allegedly conducting research on residents without agency permission.

A state Human Services spokeswoman said Tuesday the department is wrapping up its investigation of Dr. Philip May and his wife, Robin Davidson May, of Oxford.

The Mays are accused of giving vitamin D supplements to residents of the Hunterdon Development Center in northwestern New Jersey as part of unapproved research. The Star-Ledger newspaper, first to report the investigation, said high doses were involved.

The Mays have been on paid leave since December.

Lawyers for the doctor and his wife say the allegations are untrue. The doctor's attorney says he was treating his patients, not conducting an experiment on them.

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