[6] Mutumba himself reported that he turned down a deal from Deportivo La Coruña, and British media claimed he signed a short-term contract with Hibernian.

In a 2009 interview with Swedish newspaper Aftonbladet he stated that the deal with Deportivo La Coruña fell through due to problems on behalf of his agent, and he explained that they were talking about the development team, Fabril, who play in the Spanish Segunda B division.

In the last game of the 2009 season AIK beat IFK Göteborg 2–1 in a dramatic title-deciding match, claiming the Allsvenskan championship for the first time in eleven years.

In the match 55th minute, Mutumba provided the assist to his teammate Antônio Flávio, who took the "skillful" feed and rifled the equalizer past IFK Gothenburg's goalkeeper.

[9] Two days before the final game, Mutumba tattooed in "AIK GULD (Gold) 2LAX9 (2009, LAX is slang for thousand) on his chest.

Manager Mikael Stahre left for Panionios GSS and the team came under heavy criticism for its poor performances.

On 28 June 2010, media reported that the Hungarian club of Videoton FC had bought both Bojan Djordjic and Martin Mutumba.

When he originally signed on with AIK, still a teenager, his father quit his job and the young Mutumba provided the family with the only income they had.

He is second cousin with former footballer Moses Nsubuga who played for IF Elfsborg and lost his left leg in a car accident 1997.