1997 Honda Other Leek in boot

Hi there

I'm having a leek in my Honda integra boot, the water is making its way into the boot and going down to the spare tire, and making my back seats wet too, there is a whole in the top right corner in the boot as you will see in the picture added, I've jumped in the boot and got the hose over the boot too see if that's problem
And the water is coming in from that whole, people saying check your Tail lights, ready have they are fine, I don't have a sun roof so it's not that, can you please help
Me to find out how it's getting into the boot from outside to get in that whole

Thanks Jordan