At the 1964 Summer Olympics held in Tokyo, Japan, Svensson won a silver medal in the light heavyweight class.

Svensson also served as the defense attorney to Lars Tingström (known in Sweden by the nickname Bombmannen, "the Bomb-Man"), who was later convicted of three bomb attacks around Stockholm.

In the purported testament, Tingström wrote that he had given Christer Pettersson the instructions to assassinate Swedish Prime Minister Olof Palme.

The journalist Gunnar Wall wrote an article in Dagens Nyheter where he accused Svensson of manipulating the testament from Tingström.

Svensson's information led the prosecutors to file an application for a new trial against Pettersson for the assassination of Palme, but this was rejected by the Supreme Court.