How to deal with non-cooperative team mate?
This attitude is very common in academia, as the academic environment is often highly competitive. That said, I've never seen someone do that within a team. I agree with seteropere that if this person is indeed on your team, you will likely have to raise this issue with your supervisor.

Still, there's likely a reason why he's unwilling to share, and if you can find the reason for that you may be able to convince him to be more of a team player. Is he worried that giving you access will hurt his publication chances? You can work with your supervisor to convince him that he will still get authorship even if the code is shared. Is he afraid you'll ruin the code? Suggest using some sort of versioning to keep track of changes. Is he just being a jerk about it? If so, then it just comes down to seteropere's answer, and you'll have to hope your boss has enough of a backbone to help you out.