A shipment containing 16 kilograms of cocaine was seized last week at the United Nations's mail intake centre, a New York Police Department spokesman said on Thursday.

Paul Browne, NYPD's chief spokesman, said the drugs were in a white bag evidently masquerading as a diplomatic pouch that raised suspicions when it was being scanned because it was stamped with what looked like a poorly copied version of the UN logo.

Browne said here was no name or address on the shipment sent from Mexico City through Cincinnati.

UN security officials called the NYPD and Drug Enforcement Administration, which confirmed the substance inside the shipment intercepted on 16 January was cocaine, the police spokesman said.

The UN undersecretary general for safety and security, Gregory B Starr, told reporters on Thursday evening that "there is nothing to indicate that this had anything to do with anybody at the United Nations."

Starr said the drugs were actually stashed in two bags that were stamped with the sky-blue UN logo of a world map in an apparent effort to disguise them as diplomatic pouches, which are not supposed to be inspected. Inside the bag, the drugs were hidden in hollowed-out notebooks, he added.

The UN official showed journalists a photograph of the bags that were seized, and compared them with a real diplomatic pouch used by the UN, which is larger and made of a different material.

"This did not come from a United Nations facility," Starr said of the shipment.