One brief but unforgettable moment in The Godfather Part II has intrigued fans for decades - the chilling line delivered during an assassination attempt on Frank Pentangeli. As Tony Rosato, played by Danny Aiello, sneaks up behind Pentangeli, portrayed by Michael V. Gazzo, he slips a garrotte around his neck and growls, "Michael Corleone says hello." What many don't know is that this line was never scripted.

In a 2014 interview with American journalist Charlie Rose, Aiello opened up about the origin of that now-famous phrase. "I checked the internet now, and there's one question that's been raised by everyone on the internet. Was the line that Danny Aiello said in Godfather 2 an improvised line?" He went on to explain the scene in detail: "Well, let me say, the line that they're talking about is 'Michael Corleone says hello'. Now, Frank Pentangeli, who was played by Gazzo, Michael Gazzo, was sitting at a bar. I walked behind him. I come, I put a garrotte around his neck, and I say, Michael Corleone says hello, and I drag him into a phone booth. I fail to kill him."

Aiello continued: "We're rehearsing the scene. Francis [Ford Coppola] is there. I was somewhat intimidated - Francis, I'm so sorry. I was so intimidated by the man, knowing the things that he had done, and here I am, a neophyte actor."

The actor revealed that the line simply didn't exist in the script. "Now, the line, there was no line there. When I was coming behind him with the garrotte to choke him, there was no line whatsoever."

During rehearsal, Coppola called for the action, and Aiello found himself instinctively adding something. "So he said, let's rehearse. Action. So I come behind him, and I suddenly said, 'Michael Corleone says hello'. I had no idea why I said it, but I said it."

Coppola immediately called "cut" and asked, "What'd you say?" Aiello recalled, "I thought I was in trouble with the director. I didn't know what the hell I said." Nervously, he replied, "Well, Mr. Coppola, I think I said 'Michael Corleone says hello'."

The director's response was simply, "Good, keep it in."

Aiello described the improvised line as having "a history behind it," noting how fans have long been curious about its origins. "People are asking questions about it," he said. "I didn't think it was that interesting."