Prince Ali Bin Al Hussein pointed the finger at Sheikh Salman bin Ibrahim Al Khalifa, the head of Asian football, over allegations from human rights groups.
Sheikh Salman is a member of the Bahrain royal family and has attracted opposition from human rights organisations - including Americans for Democracy & Human Rights in Bahrain (ADHRB) and the Bahrain Institute for Rights and Democracy (BIRD) - due to the regime's role in the suppression of the country's pro-democracy demonstrations in 2011, which saw some footballers imprisoned and allegedly tortured.
BIRD alleged that Sheikh Salman was the head of a committee that was established in 2011 to identify and apply sanctions to individuals and clubs who had been deemed to have been involved in the protest movement.
Sheikh Salman denied any involvement and insisted that the committee never met or took any decisions on the matter.
"When people talk about skeletons in the closet, my closet is clear," he said last month.
''Some people have an agenda but it's a waste of time trying to answer them, and I think it has already been done by the proper bodies within FIFA and the AFC.
''There has been an integrity check and I don't have anything to defend myself about.''
However, Prince Ali told a news conference in Geneva: "The simple, basic fact of the matter is that person did not protect or stick up for his players at that time."
Prince Ali's comments will intensify the rivalry ahead of the election on Friday 26 February. Three other candidates, UEFA general secretary Gianni Infantino, France's Jerome Champagne and Tokyo Sexwale of South Africa are also standing.
Prince Ali was defeated in his previous attempt to land FIFA's top job, losing out to Blatter last May before the long-serving incumbent announced his intention to step down as arrests of high-ranking officials marred the organisation's congress in Zurich.
Blatter and UEFA counterpart Michel Platini are now suspended from all football-related activity on account of a $2.65 million FIFA payment authorised by Blatter to the former France captain in 2011, which was deemed a breach of conflict of interest regulations by the independent Ethics Committee.
Prince Ali insisted he was a genuinely independent candidate who would ensure that FIFA- which he insisted was an organisation in crisis and needed "a real culture change" - had the proper reforms.
"This election will determine whether a small group of powerful individuals will hold FIFA hostage," he said, at a news conference to brief on the main tenants of his prospective presidency.
"This is for people who are tired of the old way of doing things. Today I'm presenting a practical plan for implementing my vision.
"It contains concrete steps, no gimmicks, just a realistic road map that will lead FIFA to a better place and will earn the trust of football fans. A place where we will have headlines for football, not for scandal - it is about getting back to football.
"I believe in what FIFA can do and I'm trying to save the organisation and bring it back on track.
"There is a call around the world to change the organisation and this is our last chance to get it right. February is the most crucial date in history of governance of the sport."
Prince Ali's proposals include restricting presidential reigns to two four-year terms, promoting women's rights and equality in football and offering full co-operation to the ongoing US and Swiss investigations into football corruption.
"The world is cleaning FIFA up, whether FIFA likes it and FIFA can help with a real culture change," he said.
"There are so many good people in FIFA but many feel fear, and with good reason. The 209 members know FIFA is in crisis. Will a small group of FIFA members hold FIFA hostage?
"I want to see football run the right way. Less than a year ago many European countries joined with me to change a president.
"With Europe's help we can finish the job. I'm there to unite the world. In terms of integrity, responsibility and a proven record, I believe I'm the best person to lead FIFA."
Prince Ali said if elected he would contact the US and Swiss attorney generals to offer the world governing body's full co-operation into their investigations into FIFA-related corruption.
Prince Ali brought along Musa Bility, the Liberian FA president who was prevented from standing for the FIFA election after failing integrity checks, to the news conference.
Bility claimed there was "interference or intimidation" over the African football confederation's (CAF) executive committee's announcement last week that it has endorsed Sheikh Salman. He insisted the CAF's decision did not bind any African country to support the sheikh.