Fatoma has become the largest thorn in the side of Sierra Leone's politicians for demanding greater transparency about public finances in a country riddled with corruption, just over a year before elections.
The sharp-suited rights defender, who is in his 30s, risks being charged with serious offences, lawmakers have warned, although the government's own auditors have found grave inconsistencies in spending by members of parliament.
"I have been harassed, threatened, spat upon, abused, lampooned and vilified for my organisation's legitimate right to ask questions of those who have been entrusted with the future of Sierra Leone," Fatoma told AFP.
The campaigner appeared on a January 31 radio show in which he challenged the government and the anti-corruption commission to do more to make authorities accountable, in a system that he says answers only to itself.
Since then Fatoma has been arrested, bailed without charge, and summoned twice to parliament to answer questions -- yet denied an audience when he showed up.
Fatoma, a Sierra Leonean national, divides his time between his country and Britain, where his family reside.
His Britain-based non-profit organisation, the Campaign for Human Rights and Development International (CHRDI), was behind a report released last year that found 120 billion leones ($16.1 million, 15.1 million euros) was spent by parliament in the last five years, with no clue as to where exactly it went.
"There is no supporting evidence to show how these monies were spent," he told AFP, adding that the opaque nature of the legislature's activities carried a high risk of fraud.
- Ebola funds unaccounted for -
Polling firm Afrobarometer found last year that four fifths of Sierra Leoneans consider their economic and living conditions "very bad". A similar percentage thought government efforts to narrow the wealth gap were not working.
With presidential and legislative elections expected in March 2018, politicians are nervously watching their backs for allegations of misbehaviour.
Fatoma's passport has been seized, leaving him unable to return to Britain, a move his lawyer thinks is a deliberate strategy to wear him down.
Emmanuel Saffa Abdulai said that while parliament had told the campaigner his problems would stop if he simply apologised, he advised his client to refuse.
"It also violates the rights of citizens to hold their elected officials accountable," Abdulai told AFP.
Cyril Juxon-Smith, parliament's chief press officer, told local media that Fatoma was "recklessly casting aspersions" and had grossly overestimated funds given to MPs.
Furthermore, he said, the government's own audit would give lawmakers a clean bill of health, though previous internal assessments have been far from squeaky clean.
In 2015, government auditors found that just 29 percent of recommendations were followed by eight ministries and departments being monitored.
In addition, 30 percent of Ebola funds under parliament's control could not be accounted for, they said, amounting to $5.7 million.
More than 3,500 people died in Sierra Leone during the Ebola outbreak that hit in 2014, overwhelming a creaking health system and shattering an already fragile economy.
Opposition MP Frank Kposowa has claimed that demands for financial help from lawmakers meant that their allowance could barely cover costs, in spite of discounts on travel, fuel and food.
"The culture in Sierra Leone is that people approach you for help with their marriage and funeral ceremonies, school fees and hospital bills," he told journalists.
- 'Absolute poverty' -
Kposowa warned that Fatoma's actions could leave him open to the charge of seditious libel, under an arcane law long used against investigative journalists and supposedly under reform.
The British government has described the law's use as "denting Sierra Leone's international reputation as a modern, democratic country."
A child born today in Sierra Leone can expect to live an average of 48 years, 70 percent of youth are unemployed or underemployed and almost two-thirds of the population live below the poverty line, according to the United Nations development agency.
"I believe that the absolute poverty under which the majority of Sierra Leoneans live at the moment is the greatest violation of their rights as human beings," Fatoma said.
In a country riddled with corruption, most Sierra Leoneans consider their living conditions "very bad"
The daily grind imposed by hardship "compromises their capacity to be effective citizens and makes them vulnerable to bad governance and corruption," he added, playing down threats to his mission.
"This is a lifelong commitment to make Sierra Leone a better place and nothing will stop us."