Andrew Andronikou, the administrator appointed when the club went into administration last Friday, told Sky Sports News: "We are having to go to court to show that the debenture is valid.
"I don't understand the exact reason why this is, we're just following normal protocol. We are not unduly worried.
"It's not standard procedure but I'd imagine that HMRC are basically crossing their Is and dotting their Ts. We are expecting the administration to proceed."
Andronikou had been due to meet Premier League officials on Tuesday to try to find a way around what should be an automatic nine-point deduction for going into administration but that meeting has now been postponed until the result of the High Court case is known.
Portsmouth are bottom of the Premier League and their debt is estimated by Andronikou to be around 78 million pounds and their plight should be a wake-up call for all of football, the Government's Culture Secretary Ben Bradshaw said on Monday.
"We do think that there remain some very tough questions for the football authorities to address, given the events at Portsmouth and elsewhere, issues around debt, around takeovers and strengthening the whole financial governance of football," Bradshaw told Parliament.
"We are still waiting for the full implementation of the Burns recommendations (the result of Lord Burns' inquiry into the running of the game five years ago).
"Some of those recommendations have been implemented and we welcome that, but the football authorities do need to make a move on.
"I think what happened at Portsmouth should act as a real wake-up call for them to do so."
