Since then it has been 49 years of waiting, hoping and praying for the iconic freedom fighter to reappear. Hopes of his shadow darkening the doorstep of his thingira have dwindled significantly.
To some of his children, grandchildren and great-grandchildren, this may happen one day. But to some relatives, the happenings shortly before his disappearance inspire little confidence, Karumba is gone forever.
His 83-year-old daughter, Philemona Njambi remembers the last time she heard him from the kitchen window of their house in Kariokor mumbling to his friend Muturi Kahia.
"Why is Kenyatta doing this? I cannot accept this. He wants me to take Sh1 million but what about the other four people? We were all in Kapenguria and everybody deserves to be treated equally," he remarked.
Karumba had been arrested on October 20, 1952, alongside Jomo Kenyatta, Paul Ngei, Achieng Aneko, Fred Kubai and Bildad Kaggia. The six were tried in Kapenguria and jailed for seven years for organising Mau Mau activities.
Transport business
Disinterested in politics, Karumba concentrated on his businesses mostly in transport. Before the trip, Karumba's happiest moment was on Saturday, June 8, 1974, when he attended a colourful wedding of his fourth daughter, Rose Njeri Ndungu from his third wife, Esther Wanjiru, at PCEA St Andrews Church Nairobi.
The following morning on June 9, he visited Njeri at around 7am at her new home in Ridgeways and informed her that he was headed to Ruiru where President Kenyatta had a function.
From Ruiru, Karumba drove to his farm at Gwa Kungu near Nyahururu and later travelled to Uganda with his son Karanja.
Newspaper reports attributed to his host in Uganda indicated that Karumba allegedly fell afoul with a powerful businesswoman, Margaret who was a girlfriend of a senior military officer in President Iddi Amin's government.
There are claims the woman had refused to pay some money for goods Karumba had delivered and reported him to her notorious general who had Karumba arrested and killed and his body dumped in a forest.
Njambi, who at the time was working at State House in Nairobi, is unconvinced that her father was killed in Uganda. She is convinced that his misfortunes was linked to his business partners and soured relations with Kenyatta's inner circle.
Powerful politicians
Some reports claim Karumba was clandestinely brought back to Kenya where he was questioned by some powerful politicians in Kiambu. During interrogation, he slapped a senior politician who in retaliation killed Karumba and secretly buried him in a tea estate in Gakoe. Six witnesses were also eliminated.
According to the family, by the time Karanja who was met by CID offers at the railway station and questioned briefly upon arrival home from Uganda, everybody knew Karumba's fate.
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One year later, a letter was delivered to his office which also served as the command post for his flagship transport company Mwananchi.
"When I got the letter I was excited... the letter indicated that my father's pick up had been seen at a garage in Uganda. There had been attempts to repaint it but my father's name and address were still readable," Njambi says.
She took the letter to State House and handed it to Eliud Mathu, State House Comptroller who delivered it to Kenyatta. Mathu and Njambi were not strangers since the latter was Karumba's business associate.
Mathu, Karumba, Mutu Kangari as well as Kenyatta's son, Peter Muigai were partners of Nairobi Ranch company.
A letter dated January 3, 1974, by Kenya Registrars Limited to Kangu Karumba states: "We are holding your share certificate for your shareholding in Nairobi Ranching Company Limited." The letter was seeking directions on whether to send the share certificate to Karumba's address.
Documents show the other shareholders were Muigai, Mathu, and Kangari who all had equal shareholding of Sh20,000 while Karumba had contributed Sh10,000.
A few days after delivering the letter, Kenyatta saw Njambi when he was doing rounds in State House and acknowledged that he had been given the letter.
"Njambi," Kenyatta said, "Ni ndona Marua. Uhoro ucio ni ngutuiria (I have seen the letter I will have the matter investigated."
According to Njambi, who worked at State House as a seamstress up to 1999, the matter was never resolved.
One of Karumba's grandson, Tevin Nazario Ndung'u has unsuccessfully petitioned State House, Kiambu County, Heroes Council as well National Museums of Kenya in a bid to construct a mausoleum.
Honour patriarch
The closest the family got in honouring their patriarch was with National Musuem of Kenya, which was at some point willing to assist but on condition that Karumba's descendants forked out Sh14 million as consultancy and administrative fees.
In return, NMK was to provide expertise and conduct research and curate the exhibition, procure contractors for showcases and mounts, interactive, lights, audio-visuals, artworks, printing of texts and graphics for the exhibition and pay for them directly.
Since the family does not have the money, it will have to contend with Karumba's name being confined to a dusty town, Gwakung'u, near Ndaragwa, owing to the land he never had an opportunity to farm as they hope that one day, the government will deem it fit to honour all genuine heroes.