Resega's death resulted in Colombo's extremist faction prevailing over the moderates; he appointed one of his men, Dante Boattini, as the new federale of Milan, having him cancel all the plans for the dissolution of the "Muti", and even replaced the local police chief.

On 7 June Colombo was slightly wounded during an ambush near Brossasco during an inspection round in the Cuneo area, and on 14 August, assuming direct command of the "Baragiotta-Salines" Special Company, he participated in a roundup in Varzi, in the province of Pavia.

On 25 September 1944, therefore, a company of the Muti Legion under the command of Major Luciano Folli, on the orders of the Milan police chief and following the direct intervention of Mussolini, arrested the members of the Banda Koch and imprisoned them in San Vittore.

After this Koch, who had temporarily escaped arrest, accused Colombo of being "a puppet in the hands of [Enrico] Varenna", an industrialist and financial backer of Roberto Farinacci as well as a close friend of Raffaello Riccardi, former Minister of Finance, and of Piero Parini, prefect of Milan.

Having lost contact with Mussolini, who in the meantime had left for Menaggio, Colombo's column made a deal with the National Liberation Committee to obtain free transit, but on the morning of April 27 the partisans blocked the road near Cernobbio, demanding its surrender.

The trio was accompanied by Giovanni Dessy, a former naval officer now working as a secret agent for the Allies, carrying a safe conduct; in Cadenabbia, however, their car ran into a partisan checkpoint, where Colombo was recognized.