Australia's Bernard Tomic has been ordered off a practice court by a police officer in a bizarre incident at the Washington Open.

Footage has emerged of a police officer approaching Tomic's hitting partner Viktor Troicki, who told the players to vacate the court due to severe weather in the area.

In the video, the policeman walks into the middle of the playing area and tells the players to "get off the court".

Troicki, famed for his recent Wimbledon outburst at an umpire, waves his arms towards the sky complaining about the apparent lack of rain, before the policeman responds "Do you want to knock it off now? Knock it off. Leave, come on. Let's go.

"I didn't ask for your permission [to get off the court], I'm telling you."

At this point, Tomic approaches from the opposite side of the court with a cutting observation.

"Excuse me, sir, but it's not raining."

The argument continued for about a minute, with an irritated Tomic told that it did not matter if it was not raining at the time.

Tomic can be heard asking the policeman "Why are you getting so close to me?" as Troicki heads off to get his equipment.

The players eventually cleared the court, shuffling off in bemused fashion.

It proved to be a poor interruption to Tomic's preparations, as he bowed out of the Washington Open this morning in the third round.

Tomic lost 7-6 (7/4), 6-3 to Croatia's Ivo Karlovic.

The Australian had no answer to the 211cm-tall Karlovic's booming serve, with the Croatian sending down 21 aces and conceding just 10 points from his service.