Kirumira had claimed he had received death threats.
Ugandan MP Robert Kyagulanyi, alias Bobi Wine, has blamed the killing of a senior police officer in Uganda on the ongoing political tension.
After news of Mr Muhammad Kirumira's assassination broke on Sunday, Mr Kyagulanyi took to his social media account to mourn and accuse the government of the crime.
"My brother Afande Kirumira, today you're being laid to rest at only 35 years of age. I am still struggling to believe that you were shamelessly murdered in cold blood. Your only crime was speaking truth to power, fighting for justice and loving your country. They were so crude," he wrote on Facebook.
The MP for Kyadondo East is being treated in the U.S for injuries he allegedly sustained while being detained by security officers last month.
Mr Muhammad Kirumira and his female companion were murdered on Saturday night near his home in Bulenga, Wakiso District, by gunmen who were purportedly travelling on a motor bike.
Mr Kirumira was a critic of former police boss Kale Kayihura. He said he had received death threats.
He had been suspended from his role as district commander in January after accusing his colleagues in a Facebook post of corruption and working with criminal gangs.
Mr Kyagulanyi also took the chance to mourn the death of his driver Yasin Kawuma who was shot dead during Arua Municipality by-election campaign chaos last month.
"Today I kept looking at the last picture we took together, seated in the Toyota Tundra. You were seated at the exact spot where Yasin Kawuma was murdered by the same people we pay to protect us."
Mr Kyagulanyi further said they shared the same dream of unshackling Uganda from oppression by promoting equality, unity and social justice.
Nevertheless, he said Mr Kirumira's murder will not derail their efforts.
"They have killed you but they have not stopped the struggle. You stood for what you believed in. It is better to die on your feet than live on your knees. We shall never give up bro. We shall never let you down. We shall be free or die trying. May you rest in power."
On Sunday, police spokesman Emillian Kayima said: "The Uganda Police Force is greatly concerned with the assassination of assistant superintendent of police Muhammad Kirumira at Bulenga last night."
"He was with a lady whom we have been informed is not his wife but someone he knew, and she too succumbed to bullet wounds in the hospital where she was rushed for treatment."