Can I replace the 'thing' that the excess water drips into at the back of m?

There has been a horrendous putrid odour which we have isolated to the back of our 8 1/2 year old Hotpoint Iced diamond larder fridge. THere was some foul liquid collected on a dish thing which is badly corroded and is attached to some motor looking object. I want to know if it's possible to replace it. It sits directly below a hole where water drains oyt presumably. Any advice, I've filled it with dry bicarb for the time being to see if it will neutralise the smell. (My twins made their own lunchboxes one day and inadvertently knocked over some creme fraiche which got every where. Much appreciated any suggestions,