Heather Mills reportedly flew into a rage when partygoers refused to listen to her speech.
The former model was due to talk about the cruelty of puppy farms at a New York party in support of a book about animals, but launched her verbal assault on guests when they continued to speak over her.
She reportedly ranted into the microphone: “Listen up at the back. I haven’t been up for 24 hours and flew here from London to be ignored.”
Later in the evening, she is also said to have complained about the reception she received, saying: “People go to these events, have a drink and leave.”
Heather’s divorce from former Beatles legend Sir Paul McCartney was finalised last month, following a string of bitter exchanges since their 2006 split.
Heather – who was criticised by the judge in their hearing as “unreliable” – won a reported UKP24.3 million settlement from Paul.
She was recently seen holidaying in Tenerife as Paul made his first public appearance with US millionairess Nancy Shevell.