"That is completely false," Gore said in an interview with the Spanish news website "Religión Digital" (Tuesday).
According to the author, whose book was published in Spain on Wednesday, he did not lie to or deceive those responsible at Opus Dei.
On the contrary, the organisation broke off all contact with him when it became clear what serious allegations his research had brought to light.
In his investigative book, Gore accuses Opus Dei of dubious financial transactions, abuse of power, human trafficking and close relationships with far-right forces in the church and society.
Gore had previously told the Spanish newspaper "ABC" that the organisation had already been given access to the book "Opus" some time ago and had had it checked by lawyers for false allegations.
Opus Dei contradicted this statement: neither the author nor the publisher had given Gore the opportunity to view the manuscript of the book, according to a statement issued by the organisation at the beginning of October.
Gore had thus broken a promise he had previously made.
The journalist had been researching the finances of Opus Dei in Spain since 2022.
According to the Prelature, he told the organisation that he wanted to write a biography of the banker and Opus Dei member Luis Valls Taberner, who died in 2006.
Valls was chairman of the major bank "Banco Popular" and was known as a philanthropist.
As a numerary, he lived unmarried.
Opus Dei provided Gore with numerous documents for his research on Valls and enabled him to talk to around 200 members in several countries.
"I could not close my eyes"
The community rejected Gore's claims that it was involved in the management of the "Banco Popular" or exercised political and economic influence.
Members of Opus Dei would not represent either the organisation or the Catholic Church in their political activities.
The community also rejected the other results of the research that the journalist recorded in his book.
It suggested that it had been deceived by Gore.
However, he told "Religión Digital" that the subject of his book had changed as a result of his findings on Valls: "I couldn't close my eyes, I had to tackle this bigger story."
Gore accused much of Opus Dei 's leadership of hoping for a successor to Francis who would be more "friendly" to the community.
The current pope has the goal of ending the abuses in the organisation, but has not yet cracked down hard enough.
The statutes of Opus Dei are currently being revised after changes became necessary in 2022 following a decree by Pope Francis.
Opus Dei ("Work of God") was founded in 1928 by Spanish priest Josemaría Escrivá de Balaguer y Albás.
The community, which is considered conservative, consists of lay people and priests.