The reason for Carruthers's apparent change of heart is unclear. Neither Carruthers nor his lawyer, Scott Rosenblum, responded to requests for comment. A spokeswoman for the US attorney's office in St Louis said prosecutors would not discuss the case. Several other Betonsports executives are still pleading guilty, including the company's founder, Gary Kaplan.
The development will come as a surprise to Carruthers's supporters who had hoped that he would be allowed to return home on Friday. His lawyers were expected to argue that the 52-year-old businessman has effectively served his agreed sentence of 33 months through his hotel confinement on $1m bail since August 2006.