One other thing.
He says he met this girl (in the UK?), but then she said she had to go off and work in Nigeria for a charity.
I think it unlikely she actually went to Nigeria, she probably just sent his details to her scammer friends in Nigeria and they have been talking to your fiend ever since.
While he may THINK he is exchanging emails with this girl it is more likely he is exchanging emails with a 50 year old Nigerian man, sitting in a room in Nigeria full of computers with loads of other Nigerian men and women sitting at them.
They will be carrying on multiple scams at the same time with numerous mobile phones in front of them, and numerous email logons that they send and receive emails from.
So your friend may be thinking he is conducting a long distance relationship with this girl, but she is probably still in the UK signing up other scammers, and you friend is actually talking to a differnet person.
I am afraid your friend is about as gullible as they can get.
Tel him to read this "Romance Scam" section on Wikipedia
http://en.wikipedia.org/wiki/419_scams#Romance_scam