Married twice, the 57-year-old had been at the home of the second wife at Polhengoda prior to being admitted to hospital on January 20 by the husband of one of the two daughters from the second marriage.
He has three sons from the first marriage, and one of them complained to Cinnamon Gardens police that Pathirana was missing since January 23.
Cinnamon Gardens police referred the complaint to Kohuwela police.
Pahirana is from Dodampe in Ratnapura.
He has gifted a 22 carat blue sapphire to Queen Elizabeth II when she visited Sri Lanka in 1981.