Thanks for the reply. Took the fairing off today to see what I could find and it turns out it's an external leak. Probably due to old hoses and/or insufficient clamps. Found blue Castrol all over the engine under the injector pump.

Also took the front spark plug out and turned the motor over and no oil came out. That's a relief. So it appears that my fears were unfounded and the oil isn't leaking into the cylinders.