DETROIT: A US McDonald's worker shown on video offering a homeless man a burger but instead tossing water in the man's face has been fired after the footage went viral.

“I am very disturbed by the inappropriate behavior of this employee," franchise owner Wise Finley said Tuesday in a statement. "This type of behavior is not tolerated in my organisation.

"I expect my employees to treat everyone with dignity and respect, and this was unacceptable," Finley added. "This individual no longer works for my organisation."

The video, which was posted last week on LiveLeak and Facebook, sparked outrage on social media. It shows the former employee, who was not identified by the company, talking with a drive-through customer at the restaurant on the city's west side when he then shifts his attention to a homeless man.

"Hey Willie, come here, you want a sandwich?" the worker is heard saying, while holding what appears to be a hamburger box in his hand. "I'm about to help you."

As the homeless man approaches the drive-through window to take the food, the employee tosses a cup full of water in his face.

"Why you do that?" the homeless man is heard saying as he walks away.

Laughter can be heard from inside the drive-through customer's car, which is where the video was shot from.

The video posting on LiveLeak included a caption that said, "Videographer states that he did this as payback because the panhandler had earlier argued with a McDonald's customer." It was viewed almost 173,000 on that website as of Tuesday.

Many online viewers of the video expressed anger at the actions of the employee.

Officer Shanelle Williams said the Detroit police are looking for the homeless man to see if he wants to press assault charges against the former employee.