Hi Thanks for the replies. The crank is the FSA Gossamer, shown in the image above (thanks Bianchigirll). So i've just checked and i was wrong it appears that the play was from the crank arm (left) coming loose again. I took the crank entirely off and found a lot of 'crud' or 'crap' between the spline and the edge of the bottom bracket. Possibly getting down there from when it initially came loose, preventing me from ever tightening it fully again? Iv'e removed most of this 'gunk' now. I Checked the play on the other crank arm and there was none even when the left crank was off, so i'm guessing the bottom bracket is tight? I could see no visible damage to the spline or 'splinal' grooves in the crank arm. DiabloScott/DannoXYZ, i did ride on it a while when it is loose i.e. miles, but i couldnt see and metal distortion or shavings. Bianchigirll there is no fastening method on the other crank that i could see. gyozadude Surely if iv'e damages the crank arm, i will have damaged the spindle (spline)?

thank you all very much. Unfortunately can't upload any pics at the moment as don't have a camera, can source one tommorow if still required. Good night