A linguistics professor has given evidence in the trial of a man for the murder of Essex teenager Danielle Jones.

Professor Malcolm Coulthard of the University of Birmingham told Chelmsford Crown Court there were differences between language used in text messages sent from her mobile phone before she disappeared and afterwards.

It is thought to be the first time an English expert has been called to analyse text message language in a murder trial.

The prosecution alleges the later messages were sent by the 15-year-old's uncle Stuart Campbell, who denies abduction and murder in June last year.

Danielle Jones went missing in June last year

Prosecutors say Mr Campbell, 44, sent himself two messages from her phone after he had abducted her, in an attempt to throw police off his trail.

Among the key differences in texting language highlighted by Professor Coulthard was the misspelling of the word "what".

He said that in one of the messages received after she went missing it was spelt "wot", whereas her usual spelling before her disappearance was "wat".

Danielle has not been seen since she left her home in East Tilbury, Essex, to catch a school bus.

Her body has never been found.

The court has already heard prosecution allegations that Mr Campbell, of Grays, was obsessed with his niece.

The hearing continues.