Do a Black Balance and see if it disappears. It maybe a hot pixel. Dead pixel is a white color. Dust on the sensor is a dark splotch. Red is usually sign of a hot pixel.
I did multiple black balance but your point stands, is it possible to dust on the sensor? When I connect the camera via HDMI to my 55'' LG TV nanego is a black mark
Look through the glass and spin the ND-Filters you'll see dust if it's there on the filters or the sensor glass. The pixel you highlighted looks more like a hot pixel though and not dirt or a dead pixel. In your 3rd pic the dot to the bottom left looks like dust. Another thing which will really scare you is if you point the camera in the sky and expose using your aperture to the max you'll see a lot of dust possibly from the lens or from the camera if it's there. Sorry I can't help much more. I sent my cam in when I had it and Panny clean the sensor free of charge as it was still under 3yr warranty.
Fear is that a large iso does not appear anywhere else piyel and that of Manat lens when strong light is or where overly g regional point it is not visible. Babu, you have you had similar points when you pprashtal camera cleaning?