The Orange Order is refuting claims by the Garvaghy Road Residents Coalition (GRRC) that it took part in an illegal parade last night.
A GRRC statement claimed more than 30 members of the Portadown LOL No1 were able to make their way from Drumcree Church to the edge of the nearby nationalist Ballyoran estate after police had failed to turn up.
The GRRC said the PSNI only arrived when residents started to emerge from their homes. The group said it believed both the PSNI and the Orange Order had hoped to draw nationalist residents into a confrontation.
A spokesman for the Orange Order said the police arrived late but there was "no enticement" and "no illegal" parade took place.
He added: "This was the second in a series of Wednesday night protests in order to highlight the inconsistency of the Parades Commission in dealing with this dispute. Like any other Sunday protest, it was made to the PSNI, and the brethren dispersed.
"A few men went up to the head of the road and that was where the police were coming out. They told us we weren't allowed to proceed and we headed back to the church."
A statement from the Grand Orange Order Lodge of Ireland said: "We are making no comment until we find out all the facts."
A PSNI spokesman said police received reports of possible breaches of the Parades Commission determination.
"Police are investigating the circumstances," he added.
The GRCC called on the Parades Commission to "ask for a clear explanation as to why the PSNI choose to ignore or enforce a legally binding determination tonight in Portadown".