Hard to tell by looking at the photo of the tail what way the blades are pitched.
First a few qualifying questions:
Did you fly this helicopter without this problem and then suddenly this left spin began to happen?
Have you tested your gyro with the radio on but the helicopter not running (move the nose left, gyro moves tail input for right correction?
Is your gyro reversed? Is your tail servo reversed? Is your tail servo stripped? (test by holding some counter pressure on the control arm while moving the servo to full left and right)
Is the belt driving the tail in good working order? Is it slipping under load?
This is a very odd thing to happen – especially since you said you locked the tail rotor in a position that should cause the helicopter to spin right and it still goes left. Are you sure the tail is spinning the correct direction? The belt can be installed in such a way that the tail spins clockwise or by giving it a twist and replacing it on the pulley, the rotor will spin counter-clockwise.
Good luck and when you find the problem please post it so we all can know the answer.