The Oxford Cheetahs and Lions Speedway clubs have been closed with immediate effect.
Colin Horton, owner of Oxford Speedway, has been bank-rolling the club with his own money since he purchased it last year.
Colin said: "It is with dismay that I have been forced to make the decision to pull the plug on Oxford Speedway.
"The club is losing several thousand pounds each and every week and that cannot continue.
"It has got to the stage where the club is no longer a viable business. I am not here to make money for one minute, but I do not have an endless supply of cash to keep the club going and I have to put my family first.
The riders and staff of the teams have been informed and are believed to be looking for new teams.
The British Speedway and Promoters Association (BSPA) have been informed of the decision to pull the teams form the Elite and conference leagues.
The closure has been due to low attendance figures and very little interest from the local community.
Horton added: “Crowds have been in the region of 400-500 for home meetings and we value greatly the support, but the harsh reality is that we need attendances of double those figures to even stand a chance of breaking even and I just don't envisage that happening here.”