Meni, who was the head of the Otueke Council of Chiefs, died at the National Hospital, Abuja. He was 45 years old.
Until his death, he was a businessman and owned some fuel filling stations in their home state of Bayelsa.
Investigations revealed that Meni had been terminally ill for over a year before he passed on Tuesday.
When THISDAY visited his home in Otuoke, sympathisers, mostly women, were seen consoling his daughter, Vivian.
Meni's two wives and the eldest of his 12 children were said to have left for Abuja following the announcement of his death.
It was gathered that Jonathan decided to evacuate Meni to Abuja on Saturday for proper medical treatment when he noticed that his health had deteriorated.
The president was in Otuoke on a strictly private visit, which included the dedication of the Mission House of the church building donated by Gitto Construction Company when his brother's condition was brought to his attention.
THISDAY gathered that the recent flooding, which had forced the people of Otuoke to flee their homes, may have aggravated the poor health of Meni, who reportedly refused to leave his home, the ground floor of which was overran by the rampaging flood.
When THISDAY visited Meni's home yesterday, some of his personal effects destroyed by the flood, such as furniture, still littered the compound, while the living room was bare.
At the palace of the royal father of the community, THISDAY was told that the traditional ruler would not speak on the death until he was officially informed.
However, the Special Adviser to the President on Media and Publicity, Dr. Reuben Abati, confirmed the death in a statement issued tuesday.
"President Goodluck Ebele Jonathan announces with sadness the death earlier today (yesterday) of his younger brother, Chief Meni Innocent Jonathan.
"Chief Meni Jonathan passed away at the National Hospital, Abuja after a brief illness. "Formal burial arrangements will be announced later by the family," the statement said.
Hours before the official statement was issued, a source told THISDAY that the president, in company with Vice-President Namadi Sambo and the Chief of Staff to the President, Chief Mike Oghiadomhe, had visited the National Hospital when he received information about his brother's demise.
In a message yesterday, Senate President David Mark commiserated with Jonathan and Bayelsa State Government and its people over the death of Meni.
In a statement by his media aide, Mr. Kola Ologbodiyan, Mark urged the president and his family to take solace in the fact that Meni lived an exemplary life of discipline, decency and forthrightness, worthy of emulation.
"I share in this grief and pain. I pray God in His infinite mercies grants you the fortitude to bear this irreparable loss," he said.
Also reacting to news of the president's brother's death, the Bayelsa State Governor, Hon. Henry Seriake Dickson, sent a message of condolence to the president.
He led a delegation of senior citizens of the state to the presidential villa, Abuja, where he offered prayers for the deceased whom he described as a "fine gentleman and proud Bayelsan at heart, owing to his commitment and dedication to the development of not just his community but Bayelsa State as a whole."
Dickson also prayed that God should grant the president and his family the fortitude to bear the irreparable loss.
