Gearbox leak

[MYVS5LTRUTE]

Ok so I have had an oil leak and have narrowed it down to the gearbox.. It's a T56 in my VE SSV.
The leak is coming from the breather pipe on the top of the box!! as a test I cable tied a bag to the end of the pipe and took it for about a 10km drive. The pic below is the oil caught

At some stage the oil has been changed from the trans fluid to a Penrite gear oil.. The box shifts perfectly with no sign of anything wrong other then the oil leaking!!

Any suggestions on what could be causing this

 

[_R_J_K_]

Did the gearbox get filled through the shifter and overfilled maybe? Did somebody move the breather down low? Should be above the transmission.

 

[MYVS5LTRUTE]

Did the gearbox get filled through the shifter and overfilled maybe? Did somebody move the breather down low? Should be above the transmission.

Couldn't tell you about how it was filled but as it was done prior to me owning it but has been driven for sometime prior to leaking.. Breather was on top of the box..
Cant really find anything on it online.. it's a weird one..