It does indeed appear to be a Cherry Laurel, Prunus laurocerasus, though it may be a smaller cultivar rather than the full blown version, which gets 25 feet tall. Image in the link of typical Camellia leaves which are, are you can see, not so long and are more pointed at the ends, unlike your plant

https://commons.m.wikimedia.org/wiki/File:Starr_070906-8731_Camellia_japonica.jpg

Thanks very much. My mother found it growing in her garden underneath a camellia and we have been living in hope. At least we can avoid wasting any more time and ericaceous feed on it!

If it appeared of its own volition, its likely to be Prunus laurocerasus, which does get 25 feet by 20 feet, so if you don't need something that size in the garden, probably best to get rid of it. I've found the odd self set seedling of these over the years, but have never found a self set Camellia, unfortunately;-)