In this 2012 file courtroom drawing, federal defender Julia Gatto requests bail for her client, New York City police Officer Gilberto Valle, right, at Manhattan Federal Court in New York. Picture: Elizabeth Williams, File

New York -

A federal judge has overturned the conviction of an ex-NYPD police officer accused of plotting to kidnap, kill and eat young women.

Defence lawyer Julia Gatto says the judge ruled late on Monday there was insufficient evidence to support Gilberto Valle's conviction. Valle was acquitted of kidnapping conspiracy charges. He faced life in prison.

Valle was convicted in March 2013 and hadn't yet been sentenced.

A jury concluded he wasn't just fantasising when he conversed online with others he had never met about killing and cooking his wife and others in a cannibalism plot.

Gatto says the judge's “decision validates what we have said since the beginning: there was no crime.”

Prosecutors argued Valle took steps to carry out his plot, including finding people on a restricted law enforcement database. - Sapa-AP