Copyright Aid

I used a small photo on a Blog ( linked to my website ) to help inform and highlight the plight of a Dementia sufferer. The image I used from the web without permission, as I mistakenly I thought, by mentioning the photographer as his work and not mine would be ok.
Today I got an email from a company in America called Image Rights who want a massive £5,000 compensation for the image used.
I had no prior notification to ask me to remove this image first, which of course I would have done.
I am happy to pay the photographer a reasonable amount for the picture as would have been normally asked for, but do not want to pay anything like the £5k asked for.
I have read a little on copyright and it does seen that if it has been fairly used, this could help my case. The One image I used ( of his ) was part of a series of other images ( not his ) to outline Dementia help purely as an information Blog not and monetary.
Am not sure how ro now proceed with this, and would appreciate any help.

Hi tsm106,

It might be worth you reading these three threads: here, here and here as they cover the same issue as you are facing. The first thing to say is that £5000 is a wholly disproportionate amount and is unlikely to represent the true market value of the image, which is what you might expect to pay by way of damages if the matter went to court.
Unfortunately your motives, however well-meaning, for using the image do not mitigate any alleged infringement of copyright.