Cop 'plotted to kill Sri Lanka president'

A top Sri Lankan police official has been arrested over a suspected plot to kill President Maithripala Sirisena.

The alleged plot briefly threatened to cause tension between Sri Lanka and India after an Indian newspaper report Sirisena had accused India's intelligence services of involvement - a claim New Delhi and Colombo have both denied.

"The Criminal Investigation Division of police (on Thursday) arrested Nalaka De Silva after five days of questioning him," police spokesman Ruwan Gunasekara said.

Gunasekara said Silva was accused of plotting to kill the president, several senior police officials and a former defence secretary.

Magistrates on Thursday ordered Silva, a deputy inspector-general of police, be detained until November 7.