Prosecutors say there's a black market for copier toner that is making New York City businesses vulnerable to employee theft.

So far, there have been arrests in separate inside jobs at a leading cancer treatment hospital and a large law firm in Manhattan.

In the hospital case, a clerk earning a modest salary was convicted of financing a luxury lifestyle by secretly ordering $1.5 million in toner and reselling it. An employee at the law firm has been charged with stealing toner cartridges worth up to $259 a piece and dumping them for as little as $10.

The scope of the black market is unclear. But there have been isolated instances of similar toner diversion schemes in other parts of the country.