— This paper applies the modified Fisher Information Matrix (FIM) motion algorithm previously proposed by the authors to the task of locating a circular biochemical source. We develop the diffusion model for circular source and perform control theoretic analysis of the resulting FIM motion algorithm. While in our previous work we established that the source location is an equilibrium point of the system, in the present paper we show that due to consistency of the maximum likelihood (ML) estimator, the equilibrium point is unique. Simulations are presented that compare our motion algorithm to conventional concentration gradient motion algorithms. The simulations confirm that using our motion algorithm the circular biochemical source is located with a high degree of accuracy.