Birmingham City have confirmed in a statement that they can not sign players at present because of a transfer embargo.
Reports surfaced in early July that the Blues had been placed under embargo by the EFL, having allegedly failed to convince it that they were working within Financial Fair Play guidelines.
The Championship club have not made a new signing since Union Berlin left-back Kristian Pedersen joined in June.
"Unfortunately and disappointingly the EFL are currently refusing to allow us to make additions to strengthen the squad," the club wrote on their website.
"Talks remain ongoing in regard to profitability and sustainability regulations. The club has spent several months working diligently to satisfy the EFL.
"We are hopeful that a satisfactory agreement can be reached with the EFL as soon as possible to help ensure our continued competitiveness in the Championship."
Birmingham's Championship campaign gets underway at home to Norwich City on Saturday.