Private forensic investigator Paul O’Sullivan has been released on R10 000 bail..
In a statement it says a jury chose Tutu for his constant struggle for social justice and his "integrity, courage and exceptional ability."
Tutu has been active in defending human rights around the world and involved in campaigns against AIDS, tuberculosis, poverty, racism, sexism and homophobia, it says.
Tutu was chosen from 162 candidates and the award ceremony will be held on June 3 at the government palace in Barcelona.
The 82-year-old said Thursday that the award honoured him and those he described as a group of exceptionally knowledgeable and gifted activists involved in social justice across the world "on whose shoulders I have proverbially sat."