This heist was a real work of art.

A $30,000 portrait of Nelson Mandela disappeared from its creator’s Manhattan storage space, the artist said.

Conor McCreedy sold the work last month, but it was “missing” when he went to retrieve it, he said. His sketchbook — which he says is worth about $250,000 — was also gone. McCreedy has private investigators, The Alpha Group tracking it down, along with cops.