OME 1984 Problem 6

Consider the circle $\gamma$ with center at point $(0,3)$ and radius $3$ , and a line $r$ parallel to the axis $Ox$ at a distance $3$ from the origin. A variable line through the origin meets $\gamma$ at point $M$ and $r$ at point $P$ . Find the locus of the intersection point of the lines through $M$ and $P$ parallel to $Ox$ and $Oy$ respectively.