The Football League have said the PST's takeover bid is the only one they will consider despite a recent rival offer from football financier Keith Harris.
But after a brief High Court hearing on Thursday, administrators PKF revealed that correspondence between the League and former Portsmouth owner Balram Chainrai's company Portpin has led to "some ambiguity" over the League's stance.
The PST's bid to buy Portsmouth, who have been in administration for just over a year, hinges on PKF gaining permission from the court to sell them Fratton Park, which is controlled by Portpin.
Portsmouth will be thrown out of the League if they are still in administration by the start of next season, and the court deemed the case must be heard by April 19 at the latest with a date expected to be confirmed in the next few days.
PST spokesman Colin Farmery said the latest development was "unexpected", but added: "This is Pompey after all, there is always something coming out of left field.
"But from our discussions the Football League are quite clear they will only consider the bid from the PST.
"It's hard to comment on as I have not seen the correspondence but the indications from the Football League, as recently as Monday, are that they are clear on that point.
"At the end of the day we are pleased the court case is proceeding. It needs to be heard by April 19 to meet the Football League's deadline. The judge realises time is of the essence. We hope we will be in control much sooner that that.
"The PST's bid is the best one for the creditors and for the club, and means Fratton Park will be back under the ownership of Portsmouth Football Club."