On Wednesday 16 April the anonymous caller made one more call to the Chief Commissioner. This time, the police were ready. As soon as the man was on the line, D-24 sent out a call to all St Kilda detectives. They all drove around to as many public telephone boxes as they could on what was now a well-practiced routine. And sure enough, an alert local detective, Mark Caulfield, saw a man talking in a phone box. When Caulfield approached him and took the receiver from his hand, the Chief Commissioner was on the other end of the line. They had caught their anonymous caller.
The man, was an industrial chemist called Vladimir Rhychta. It didn't take police long to see that he didn't have any real information. They charged him with hindering a police investigation. It was frustrating for the detectives - they couldn't have ignored his calls, but many hours had been lost chasing Rhychta that could have been more productively used hunting the real bombers.
But with the connection between the bomb car and the bank robbery in Donvale uncovered two days earlier, the investigation had gained a new momentum.