Fans of both clubs had been told earlier this week that they would not be allowed into McDiarmid Park with either flags or banners on the grounds of safety following recent incidents of flares being smuggled into matches.
A statement on Celtic's official website claimed the ban had been lifted following further talks with St Johnstone and the police, although match commander, Superintendent Kevin Lynch, denied that any such decision had been agreed among the parties. He instead reiterated that fans would be subject to a "robust search policy" at the Perth ground.
Celtic have been under pressure from supporters' groups to have the ban removed. The police have grown concerned over the potential of fans using paraphernalia to smuggle flares and smoke bombs into stadia - with the Celtic support having been brought under further scrutiny after a smoke bomb was thrown on to the pitch during a recent league match in Motherwell. Seating at the ground was also damaged, costing the Fir Park club an estimated £10,000 in repairs.
Lynch last night intimated that it had been "disappointing" to learn that Celtic had appeared to go against the wishes of the police and invite fans to travel to Perth with banners. "We were unaware of this statement in advance of it going on the Celtic website," the police superintendent said. "It is very disappointing and it would appear there has been some confusion. There may be mixed messages but I must stress there has been no change in the policy agreed with both clubs regarding the Boxing Day fixture.
"We had a collective agreement in place with both St Johnstone and Celtic following a pre-ops meeting held at McDiarmid Park last Friday. Celtic were represented at safety officer level in discussions regarding effective policing measures. The club signed up to the previous joint statement. We agreed with the clubs and the ground safety plan measures that flags and banners would not be allowed into this particular match because of the recent incidents at matches in Scotland involving flares and smoke bombs. Nothing has changed in that respect."
The contrary Celtic statement - which in part read: "We have an excellent relationship with everyone at St Johnstone and we thank them and the police for reviewing their initial decision" - is understood to have caught officials at St Johnstone off guard. There are now concerns that the Perth club will be left to handle any fallout.
A spokesperson for the club yesterday echoed the views of the police that the banner ban had been agreed and implemented as a one-off after discussions with the authorities and Celtic. A statement read: "A decision has been taken that for this specific fixture flags and banners will not be permitted inside McDiarmid Park."
One unconfirmed report suggested the confusion had been caused by a Celtic official mistakenly calling Inverness Caley Thistle, rather than St Johnstone, and getting agreement for the later match between Celtic and ICT.
Further discussions are expected before Thursday to try to clarify the issue for fans.