Sri Lanka's president has pardoned a former Tamil Tiger insurgent accused of conspiring to kill him 10 years ago.

President Maithripala Sirisena set free Sivaraja Jenivan on Friday, which was the first anniversary of Sirisena being elected to office.

Attorney U.R. de Silva says Jenivan was arrested in 2005 inside a passenger bus leaving Sirisena's hometown Polonnaruwa.

He was convicted last year of being an accomplice to a Tamil Tiger rebel who was planning to assassinate Sirisena.

The attorney says Sirisena considered that the 36-year-old Jenivan had been detained for 10 years.

Since becoming president, Sirisena has taken steps to advance post-civil war reconciliation, including providing relief to Tamil rebel suspects.

The civil war ended with the Tamil Tigers' defeat in 2009.