Richardson (pictured racing for Swindon Robins in 2007) is believed to have been thrown head first into a solid safety fence while racing for PGE Marma Rzeszow against Betard Sparta Wroclaw.
He suffered a serious leg injury and had internal bleeding and breathing difficulties before later dying in a hospital in Wroclaw.
It is believed internal bleeding in the chest area is what ultimately killed him.
The 33-year-old from Hastings in East Sussex most recently raced in the British speedway league for the Lakeside Hammers and has represented Great Britain on numerous occasions.
The Lakeside Hammers club confirmed the news in a statement: "The Lakeside Hammers captain died today in Poland as a result of injuries sustained in a racing accident," it read.
"All at the club are devastated at the loss of a great captain, man and more than anything a wonderful father and husband.
"Our thoughts are with his family at this most sad of times and we know that all Hammers fans will share our total devastation at this tragic news."