The Toronto Transit Commission says it has identified a driver caught on film using a cellphone while operating a bus.

A 12-second video posted to YouTube by user "C Stan" on Saturday shows the driver tapping on a mobile device with one hand and steering with the other as the bus travels down a house-lined street while oncoming cars pass by.

In the video, the red colouring of the TTC's logo can be seen on the driver's sleeve, the same arm holding a cell phone not concealed by the barrier around the driver's seat.

TTC spokesperson Brad Ross told CBC News in an email that the video was brought to the TTC's attention on Friday. It was taken on the 20 Cliffside route in Scarborough, and Ross believes it was shot late Thursday afternoon.

"This is a very serious matter and the TTC is treating it as such given the enormous responsibility it has for the safety of its customers and all road users," Ross wrote, adding that a disciplinary process is underway for the driver.

CBC News reached out to individual who posted the video, but he or she wasn't immediately available for comment.

Using a cellphone while driving has always been prohibited by the TTC, Ross wrote, adding that the commission expects its employees to strictly adhere to both its policies and the law around cellphone use.

Under Ontario's distracted driving law, using any hand-held communication or electronic entertainment device while driving is prohibited. That includes iPods, mobile phones, laptops and GPS devices, among others.

A fully-licensed driver caught breaking that law can face a fine of $400 plus a victim surcharge and court fee, plus three demerit points. That fine can rise to up to $1,000 if that driver receives a summons.

On top of that, drivers who endanger others through use of a device can be charged with careless driving under the Highway Traffic Act or Dangerous Driving under the Criminal Code, which can result in a jail term of up to five years.

Ross wouldn't comment on the specific penalties the driver could face by the TTC, but said the options range from suspension to outright dismissal.