The number of people warned by Kent Police they are in danger of being murdered has soared, it can be revealed.

So-called "Osman warnings" - issued when police intelligence reveals death threats - have increased by 50% in just 12 months.

The red alerts, which also offer the individual police protection, were made 59 times in the county in 2012.

This is an increase of 20 warnings - or a jump of 50% - on the previous 12 months, figures obtained by the KentOnline under the Freedom of Information Act show.

"Why didn't you stop me before I did it? I gave you all the warning signs..." - murderer Paul Paget-Lewis

However, the figure could be just the tip of the iceberg as it only includes warnings issued by Kent Police's "basic command units" and policing divisions.

The force could not provide figures for warnings issued by officers in headquarters-based departments, such as the Serious Crime Directorate and which often deal with high-profile cases.

Kent Police said Osman warnings are issued when intelligence reveals a "threat of death has been made against an individual that could result in their murder".

Those warned are often subject to heightened police patrols and sometimes have access to emergency response buzzers.

Osman warnings were created after a legal ruling in 1998 said police have a "duty of care" to warn those in danger, even if they are known criminals.

It followed a 1988 case in which a disturbed teacher shot pupil Ahmet Osman - and killed his father and two other people.

Their murderer, Paul Paget-Lewis, later asked police: "Why didn't you stop me before I did it? I gave you all the warning signs."

Guidance given to forces by the Association of Chief Police Officers says if police have "credible information" about a threat to somebody's life, forces had an "obligation" to take preventive measures.

Kent Police would not provide a breakdown of the areas in which the warnings were given, the age of the subjects or even the date they were issued - citing rules protecting the safety of members of the public and adding the information could harm the detection of crime.