Sirisena's move to revamp his security comes ahead of the parliamentary elections scheduled for August 17.
Sirisena had continued with the same Presidential Security Division (PSD) which protected Rajapaksa during his 10-year term, including when the country was at war with separatist rebels of Liberation Tigers of Tamil Eelam (LTTE).
Minister of Public Order John Amaratunga said the PSD has been disbanded after its involvement in criminal activities,The Sunday Times reported.
The 5,000-strong PSD's role came under the cloud following a string of investigations by the Criminal Investigation Department since Sirisena's surprise victory over Rajapaksa in January.
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A PSD personnel was arrested in late April when he came dangerously close to Sirisena carrying a loaded pistol during a function. It was the worst security breach in 16 years.
It said the PSD personnel did not guide Sirisena to his official vehicle.