The document, which was leaked, recommends that UN members consider "decriminalising drug and possession for personal consumption".
It argued "arrest and incarceration are disproportionate measures".
The document was drawn up by Dr Monica Beg, chief of the HIV/AIDs section of the UNODC in Vienna. It was prepared for an international harm reduction conference currently being held in Kuala Lumpur.
The UNODC oversees international drugs conventions and offers guidance on compliance.
Sources within the UNODC have told the BBC the document was never sanctioned by the organisation as policy. One senior figure within the agency described Dr Beg as "a middle-ranking official" who was offering a professional viewpoint.
The document, on headed agency notepaper, claims it "clarifies the position of UNODC to inform country responses to promote a health and human-rights approach to drug policy".
"Treating drug use for non-medical purposes and possession for personal consumption as criminal offences has contributed to public health problems and induced negative consequences for safety, security, and human rights," the document states.
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