The swoop came 24 hours after Walter Renwick denied chainsawing the 300-year-old landmark at Sycamore Gap along Hadrian’s Wall.
Three police vans were in the driveway at Plankey Mill farm, eight miles from the scene in Northumberland, while at least seven officers conducted a search.
Mr Renwick, 68, has been ordered to quit the property where he ran a tourist campsite after losing a two-year legal battle.
During the case, he said: “I was born here. It is like a tree with roots.”
The 70ft tree — which featured in 1991 Kevin Costner movie Robin Hood: Prince of Thieves — was attacked in the dark between Wednesday and Thursday last week.
On Friday, Mr Renwick told The Sun: “I didn’t do it.”
But he conceded: “I am a former lumberjack and I have just been kicked off my property, so I can see why people have pointed the finger.”
On Friday night, Northumbria Police said they had arrested a man in his 60s and held him overnight.
And last night Mr Renwick’s family confirmed to The Sunday Times that he was in police custody.
Cops had previously arrested a 16-year-old boy on suspicion of causing criminal damage, then released him on bail pending further inquiries.
A local pub is offering a £1,500 bar tab to anyone who helps to solve the mystery.