Climate Camp demanded an apology from West Lothian and Borders Police on Sunday following accusations that the environmental group had created an oil spill on a busy road.
Activists from the group strongly denied that they caused the slick on the A8 Edinburgh-Glasgow road near the Royal Bank of Scotland headquarters.
The spill happened during a climate protest by hundreds of campaigners on land next to the bank last week.
Activists poured a molasses-based substance outside another premises in the city and superglued themselves to RBS sites.
During the protest, Lothian and Borders Police said a substance appearing to be vegetable oil or diesel had been poured on to the main road.
They linked it to the protest camp, accusing activists of putting the public at risk.
But Climate Camp has vigorously denied the allegations in a letter to police.
"This has amounted to a smear campaign against Climate Camp on the grounds of an unsubstantiated implication of putting many members of the public at risk," it said.
The group has also filed a Freedom of Information request to obtain police notes and photographs of the area at that time.
A spokesman from Climate Camp admitted that it did take part in direct action "against the causes of climate change" which sometimes "necessitates breaking the law."
But he insisted that any action was always directed at "climate criminals - banks, corporations and governments - and have never aimed to endanger the public."
Last week convener of the police board Councillor Iain Whyte said climate change protesters should pay for some of the estimated £100,000 bill for policing the demonstration.
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