git pull over ssh gives wierd errors

This is my setup.

1. My git repository is in bitbucket
2. I have created keys on my remote aws ec2 server and kept it in ~/.ssh folder
3. I then add the key via the ssh-agent on my remote server
4. Updated these keys on the bitbucket website.

When I login to my remote server and run git pull on my git repository everything works fine. No issues here.

But when I run the same the same via the cygwin bash on windows it gives me this error:

Permission denied (publickey).
fatal: Could not read from remote repository.
Please make sure you have the correct access rights
and the repository exists.

I do the following on my windows machine

ssh -i xyz.pem user@ip -t 'sudo sh deploy.sh'

Where the deploy.sh, cd's into my repository and does a git pull.

Why is this issue happening ? Should I also keep these ssh keys on my windows machine? Any help will be invaluable.