A third person has been arrested in connection with a Just Stop Oil protest at Stonehenge, during which orange paint powder was sprayed on the prehistoric monument.
A man in his 30s, from Essex, was detained by Metropolitan Police officers on Thursday, according to Wiltshire Police.
He was arrested on suspicion of aiding and abetting criminal damage, aiding and abetting unauthorised entry and damage to an ancient monument, and aiding and abetting aggravated trespass.
The man has now been released on bail.
Members of the public were seen trying to stop the protesters by dragging them away on 19 June.
Video footage showed two people wearing white Just Stop Oil shirts running up to the structure with canisters spraying paint.
Several stones were covered in the substance before the protesters stopped and sat cross-legged on the grass.
Just Stop Oil said its action was to demand the next UK government agrees a plan with other countries to end the extraction and burning of oil, gas and coal by 2030.
Following the protest, English Heritage said experts had quickly removed the powder from the stones, as there was a risk it would harm rare lichens growing on them.
There appeared to be no visible damage from the paint, the charity added, but the act of removing it could erode the fragile stone and damage the lichens.
A spokeswoman for Wiltshire Police said the two others previously arrested in connection with the incident - a man in his 70s and a woman in her 20s - remain on bail while the investigation continues.
"We are continuing to work with English Heritage and partners to progress our enquiries," she added.