PPRuNe Forums - Emirates Airline Formal Offer Question

Hello,

I got an unofficial job offer with Emirates Airline after interviewing with them. They basically told me that I was successful after the interview and that I should be receiving a formal job offer. It has now been 2 and a half weeks and I didn't get a formal offer yet. I am getting a little worried.
Is this normal? I can access the "selected candidates" page and every time I try to log in into my work application I get a message that says that I can't log on because I have an offer.

Anyone who has been in this similar situation? Any input or advice? Are they taking long because they performing a background check?

Thanks in advance for your help.

PS: This is a for an engineering position.