Harald Stabell, who successfully defended the militant Islamist Mullah Krekar from being deported to Iraq, will now look into whether those living near the site have a case to sue the Norwegian government if it is built.
"The decision is unfair and it is an inconvenience to neighbours that this place is chosen," Stabell told NRK, after sending a letter to the government warning of a potential legal case.
The Norwegian public art body Koro in February chose "Memory Scar", a concept by the Swedish conceptual artist Jonas Dahlberg, as the memorial to those who died during the terror attack on Utøya in July 2011.
The artist proposed creating a "permanent scar" of the landscape by carving a three-and-a-half-meter wide slice out of the Sørbråten peninsular.
Almost as soon as the proposal was launched neighbours set up a Facebook group, which condemned the design as a "rape of nature" , a "tourist attraction ", and a "hideous monument".
"We were forced to engage the lawyer Harald Stabell, after we were unable to reach the decision-making authorities," Anne-Gry Ruud told NRK.