Language scientists and ecologists have teamed up to help police trap criminals by reading their text messages.

They are adapting methods of studying life in the oceans to identify anonymous text authors by their writing style.

The system is expected to make its first appearance in court within four or five years.

Linguistic evidence showing who sent a particular text message has already played a significant role in police investigations.

But there is no scientific method involved - the process depends solely on an expert's personal opinion.

The new research is aimed at developing a rigorous statistical technique that can be tested in court.

Scientists are building up a database of text messages donated by volunteers to look for distinctive differences in style and language between individuals.

These can then be used to analyse anonymous messages from potential suspects.

The technique developed at the University of Aston is based on well-established ways of studying diversity in the oceans.

Linguistic expert Dr Tim Grant sought the help of ecologists who differentiate between marine environments by seeing how close or far apart they are in terms of species.

Applying the same statistical method to text messages can show how close or distant different extracts of writing are.

"We can measure similarity and difference by means of the stylistic distance between any two text messages," said Dr Grant.

"Pairs of text messages by the same author are going to be more alike. And where you get groups of people who text one another a lot, or pairs of people, their language becomes more similar.

The research will in future make it harder for criminals to hide behind anonymous text messages or use them as alibis.