[1] Horelli and Arno Anthoni, the director of the Finnish State Police, were responsible for the deportation of German refugees that were handed over to the Nazis in November 1942.

[2] Horelli was born in the Western Finnish municipality of Kokemäki to the family of Johan Fredrik Mäki-Horelli (1844–1931) and Amanda Giers (1850–1922).

[1] In the early 1930s, Horelli supported the fascist Lapua Movement, although he was not an active member, neither did he join its political successor IKL but stayed loyal to the National Coalition Party.

[1][5][6] During his term, Horelli refused to handle the applications for citizenship by people of Jewish origin,[7] and clashed with trade union leaders like Niilo Wälläri.

[8] In the fall of 1942, Horelli made a requisition for awarding the SS commander Martin Sandberger with the Order of the White Rose of Finland.

The matter was discussed on Heinrich Himmler's visit in the summer of 1942, and soon Horelli and Anthony secretly ordered the deportation of 27 refugees, including 8 Jews.

[1] In April 1945, the prime minister J. K. Paasikivi requested that certain persons would not stand as a candidate on the 1945 election due to their wartime action, and Horelli decided to leave the politics.

[13] Poland and the Western Allies wanted Horelli, Anthoni and the State Police officer Aarne Kauhanen to be included on the list of war criminals, but the Soviet Union never made a claim to the Finnish government.

[18] However, among the deported were two children ages of 2 and 11, and only two of the Jewish adults had criminal record; one had a 10-month prison term for smuggling, and another had been fined for breaking the rationing laws.