By Amber Goodhand - Breaking Celebrity News News Editor

Nicki Minaj was slated to host her album release party on Tuesday night at a club in New York City, but an eyewitness exclusively tells Breaking Celebrity News the pop diva and her entourage were denied at the door by the NYPD because they were at capacity.

Held at Greenhouse Nightclub, the event was sponsored by Smirnoff Iced Cake and Nicki, 29, was supposed to make an appearance with Flo Rida and Fabolous - but came too late to get in.

"Nicki turned up to the club with about 25 people at 3:30 in the morning," the eyewitness exclusively told Breaking Celebrity News.

"She wanted to celebrate with her fans, but she was denied entry at the door by the police because they said the venue was at capacity and there was nothing they could do to accommodate her."

Ouch!

"Nicki wasn't happy about it, so she and her group just left," the eyewitness said.