At first I thought that it could possibly a SIG P220 with an aftermarket magazine.
The details on the photo are too indistinct to tell for sure but the trigger and trigger guard look like a P220. There is too much slide sticking out the front to be a P225.
It looks like a single stack in what looks like 9mm but they did make the P220 in 45 ACP, 9mm, .30 luger and 38 Super.
The magazine however, gives it away, it looks nothing like a SIG zipperback magazine. It looks like the mag. on one of those Yugoslavian (CZ99, Z99) clones of the SIG.
So I would surmise that is what it is or the licence made copy by Tressitu (Tressitu TZ99) of South Africa. Still, most of those had double stack mags.

SIG P225

SIG "zipperback" magazine

Tressitu TZ99 with mag.
Image from here
“Never give in, never give in, never; never; never; never – in nothing, great or small, large or petty – never give in except to convictions of honor and good sense” — Winston Churchill, Oct 29, 1941