Kind hearted cabbie gets attacked

A kind hearted taxi driver has been robbed by a passenger he was giving a free lift to.

The driver felt sorry for the man who approached him in Melbourne's CBD on September 26, telling him him he had only $11 and needed to get to Ascot Vale.

But the passenger became aggressive during the trip, threatening to stab the driver and demanding cash before smashing the cab's eftpos machine.

Police on Thursday released CCTV image of the man, who fled the taxi empty handed.