Reid was followed for 200 yards by police

Police officers spotted Roselyne Reid, 38, looking at a mobile phone as she drove through central Perth.

The officers followed Reid's vehicle for about 200 yards until she got to a bus stop.

They told Perth Sheriff Court that Reid did not appear to look up to check the road ahead during that time.

When the officers boarded the bus to speak to her and charge her with careless driving, she said: "I put my hands up to that."

It was clear she was doing something other than looking at the road where she should have been looking Constable Watson Fraser

Reid, of Dunsinane Drive, in Perth, was fined �80 and given three penalty points for the offence on 18 March.

The court heard that her employers, Stagecoach, have issued her with a final warning for breaching the company policy on the use of mobile phones.

Constable Watson Fraser said: "We saw a bus which turned right and we could see the driver was using a mobile phone.

"She was looking down at the phone in her right hand. We travelled after the bus which stopped at the next stop. The driver was still looking at the mobile phone.

"There were about 20 passengers on the bus. The phone was in her hand and down towards the steering wheel as if she was maybe reading a message on the phone."

The officer said Reid, who was driving at up to 25 miles per hour, appeared oblivious to everything else.

Patrol car

He said: "It was clear she was doing something other than looking at the road where she should have been looking. I felt we had seen enough."

Constable Steven Whittet was sitting in a patrol car and saw Reid turning the single-decker bus right while she used the phone.

He said: "I could clearly see the driver of the bus holding it in her hand in her lap. Her hand was down on her thigh.

"She continued round the corner and at no time did I see her look up to see the road. The bus stopped and she still had the phone in her hand looking down at it."

Reid, who denied driving carelessly, said: "I had been reading a text message. The traffic light was red so I put the handbrake on and read it."

She alleged that she then switched the phone off before moving away.