The cost of policing a protest camp between two communities in north Belfast is around £333,000 a month, Stormont's justice minister David Ford has told the Assembly.
Violence flared in the unionist Woodvale area in 2013 when Orangemen were banned by the Parades Commission from parading past the adjacent nationalist Ardoyne on their way home from traditional Twelfth of July commemorations.
Rioting broke out on a number of subsequent days and loyalist demonstrators have maintained a continuous presence at the protest camp at the Woodvale/Ardoyne interface at Twaddell Avenue ever since.
This has required a fluctuating police presence to ensure no more trouble erupts.
Mr Ford said: "I believe it is running in the region of a third of a million pounds per month.
"All of that is money which is either being spent on additional overtime, which is creating pressures on police officers and the police budget, or it is a cost from the officers being redeployed from other duties including the basic everyday crime fighting and public reassurance that members tell me frequently they want to see in their constituencies.
"It may only be an opportunity cost but it is nevertheless a significant cost."
At one stage the bill was nearly £1 million a month but that has reduced, the minister said..
Serious violence erupted in the area in 2013 when Orangemen were stopped from marching past Ardoyne while returning from their annual Twelfth of July demonstrations.
Dozens of police officers were injured when loyalists pelted them with bricks, bottles and heavy masonry. One rioter also used a ceremonial sword to attack police lines.
Since then, loyalists have set up camp at Twaddell Avenue to protest against the Commission determination which they claimed rewarded previous violence by republicans.