fuel leak

I've had my 2005 automatic with 90,000 miles rx8 since April 2014. In December of 2014 my car stopped starting tried the deflooding process but that wouldn't work. I didn't really have the finances to fix so it sat till about February of this year, ended up swapping out my engine with an imported one. Later found out that this car had already had the engine swapped under the extended Mazda warranty. My car was driving fine after the swap only issue was the check engine light would stay on. I was told it was probably just the o2 censor since the car was blowing a lot of smoke before the swap. But the idle was fine didn't have any issues, but last night I was about to park when the car suddenly died. When I tried restarting it I got a heavy fuel smell and then noticed my car leaking fuel right by the engine over on the passenger side. Could this be something that just wasn't installed properly during the swap, like a line or is this a different problem altogether. Any help would be appreciated, this is my first time posted so I'm sorry if I posted in the wrong section.