Croydon Council used the Regulation of Investigative Powers Act (RIPA) to try to track down a builder caught cutting a Scots pine.
He had given a false address but provided a mobile telephone number.
A Croydon Council representative said: "A search for the address of a man caught illegally pruning a preserved mature Scots pine was made only after every other avenue open to us was exhausted. The man was caught committing a criminal act after complaints from residents.
"When questioned by our tree officer he gave his mobile number but with a false address."
The council has not caught the man as the mobile number was an unregistered pay as you go phone.
Since January 2004, the council has used the act on 212 occasions to investigate offences from anti-social behaviour and racial harassment, to fly-tipping and council tax fraud.
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