So this is my conspiracy theory.

They never found him.

In order not to lose face, they looked high and low for a guy who looked very much like Mas Selamat.

Then they bribed him with lots of money, threats or a combination of the two.

After he “agreed”, they took this dude for major reconstructive surgery to make him look exactly like Mas Selamat Kastari. Of course, they had to wait a number of months for him to recover an for any remnant scars to heal. 

Then they had to gently mess up his leg a bit so he would limp.

When everything was perfect, they “found” him in JB.

Cool.

(Disclaimer: I write Fiction)