Fifa whistleblower Phaedra Al-Majid says she will "look over my shoulder for the rest of my life" after making allegations of corruption against Qatar's successful 2022 World Cup bid.
In a two-year inquiry which cleared Qatar, Al-Majid repeated allegations she made and later retracted in 2011.
She told the BBC her accusations introduced her to "a whole new culture of paranoia, fear and threats".
In response, Qatar said they "stand by the integrity of their bid".
The country's World Cup organising body has always "vehemently" denied all allegations of wrongdoing.
They said a series of allegations about their conduct had been "over a period of years, investigated, tested, considered and dismissed".
Al Majid worked as an international media officer for the Qatar 2022 bid team before losing her job in 2010.
Her allegations that Qatari bid officials offered to pay for the votes of three Fifa members first came to light in 2011. Later the same year she signed an affidavit saying they were false.
She now says she was coerced into changing her statement. "I had no more legal representation," she said. "When the Qataris approached me, I was alone. I'm also the single mother of two children, one of whom is severely autistic and severely disabled."
She said officers from the FBI visited her in September 2011 after they became aware of threats against her.
"They questioned me about the Qatari bidding process and they questioned me about all the threats I had received from the Qataris," added Al-Majid. "It was decided at that point that I would help them with their investigation and it was planned that I would talk to a senior official at the Qatar bid.
"So when I talked to the official, and the FBI are recording this, he did admit that there was a deal for the affidavit that I would basically say that they had done no wrongdoing."
Al-Majid, who says she is "tired of Fifa's culture of secrecy", provided all her information to Garcia while he was compiling his 430-page report on allegations of wrongdoing in the 2018 and 2022 World Cup bid process.
But judge Hans-Joachim Eckert, who wrote the 42-page summary of findings released on 13 November, said her evidence contained "inconsistencies" which prejudiced its credibility.
In contrast, Qatar say they supplied "full and valuable" assistance to the Garcia enquiry.
Garcia subsequently criticised Eckert's summary of his findings and the pair are due to meet on Thursday.

World Cup vote corruption allegations timeline

13 November, 08:30 GMT: Fifa publishes a 42-page summary of its long-awaited report into the 2018 and 2022 bidding processes. The English Football Association is accused of flouting bidding rules in its attempt to stage the 2018 World Cup - but 2022 hosts Qatar are cleared of corruption allegations.
13 November, 12:30 GMT: Michael Garcia, the man who conducted the two-year inquiry into alleged corruption, says the summary published hours earlier "contains numerous materially incomplete and erroneous representations".
13 November, 16:30 GMT: English Football Association chairman Greg Dyke calls Fifa's report "pointless" and "a joke".
14 November, 12:00 GMT: Fifa ethics judge Hans-Joachim Eckert says he is "surprised" by public criticism of the report in to the 2018 and 2022 World Cup bidding process from Fifa colleague Garcia.
17 November, 06:00 GMT: Former English Football Association chairman David Bernstein tells the BBC the FA should lobby Uefa for a European boycott of the next World Cup - unless Fifa implements meaningful reform.
17 November, 17:00 GMT: Dyke writes to Fifa's top executives to demand Garcia's report into the 2018 and 2022 bidding processes be published in full.
18 November, 16:00 GMT: Fifa submits a criminal complaint to Switzerland's attorney general concerning individuals linked to awarding the hosting rights for the 2018 and 2022 World Cups.
19 November, 1715 GMT: Fifa whistleblower Phaedra Al-Majid repeats previous allegations of corruption surrounding Qatar bid and says she will "always look over my shoulder for the rest of my life".