A plane in the US had to be diverted and two passengers removed after one of them started a fight by using a banned device to stop the seat in front reclining.

The spat began on United Airlines flight 1462 because one passenger was using the Knee Defender, a $21.95 lock that attaches to a tray table and jams the reclining mechanism of the seat in front.

The male passenger, seated in a middle seat of row 12, used the device to stop the woman in front of him reclining while he was on his laptop, according to a law enforcement official who spoke on condition of anonymity.

A flight attendant asked him to remove the device and he refused. The woman then stood up, turned around and threw a cup of water at him, the official said.

The dispute on the service from Newark to Denver escalated to the point that the airline decided to divert to Chicago’s O’Hare international airport, according to Transportation Security Administration spokesman Ross Feinstein.

Chicago police and TSA officers met the flight, spoke to the passengers — a man and a woman, both 48 — and “deemed it a customer service issue”, Feinstein said. The TSA would not name the passengers.

The plane then continued to Denver without them, arriving an hour and 38 minutes late, according to the airline’s website.

Both passengers had been sitting in United’s “economy plus” section, which advertises four more inches of legroom.

The Federal Aviation Administration leaves it up to individual airlines to set rules about the device. United Airlines says it prohibits its use, like all major US airlines. Spirit Airlines and Allegiant Air take the reclining mechanisms out of their seats, leaving them permanently upright.

The FAA can impose a civil fine of up to $25,000 for passengers who are unruly. In this case no arrest was made, according to airport spokesman Gregg Cunningham.

Then just put your seat back. I always put mine back, mainly because of my height and it takes the pressure off my lower back.