A bus driver who groomed and sexually abused a 15-year-old girl has been jailed four-and-half years and placed on the sex offenders' register for life.

Andrew Blyth, 55, chatted with the girl after he accepted her friend request on Facebook and later sent her sexually explicit photos of himself, and allowed her to send him photos showing her partly undressed, Norwich Crown Court heard.

Andrew Shaw, prosecuting, said Blyth was aware the girl was only 15 at the time and yet sent her a message saying: 'If you were not 15 we might be together.'

He said they started chatting on Facebook after the girl saw his profile and made a Facebook request.

Blyth of North Walsham Road, Bacton, admitted three offences of sexual activity with a girl under 16.

Jailing him, Judge Katharine Moore told him there was a great disparity in their ages as he was 40 years older than the girl and said: 'There was grooming behaviour used against the complainant.'

She added: 'You knew what you were doing was wrong. You knew she was 15 and that this behaviour should not be taking place.'

Judge Moore said girls had to be protected from 'predatory behaviour' and added: 'Children require the protection of the law.'.

However she accepted he was genuinely remorseful and had a number of health problems.

She also made him subject to a sexual harm prevention order, which limits his contact with girls under 16.

Gavin Cowe, for Blyth, said the girl presented as much more mature for her age and had engaged in discussions with him on Facebook.

He said that Blyth was of previous good character: 'He cannot explain to himself why he acted as he did.'

Mr Cowe said Blyth thought his medication might have made him act more impulsively, and said: 'He knew what he was doing was wrong.'

He said the offences took place over a brief period and he was full of remorse.

He added that it had not been an easy time for Blyth, and said: 'He is a man who is not in the best of health.'