Qatar spied on a 2017 meeting between a former Swiss attorney general and FIFA president Gianni Infantino, amid fears it could be stripped of hosting last year's World Cup, a newspaper reported Sunday.

The emirate rejected the allegations, saying they were part of "smear campaigns" by European media.

But according to the NZZ am Sonntag weekly, an intelligence operation recorded the meeting in a luxury Bern hotel between Switzerland's top prosecutor at the time, Michael Lauber, and Infantino. The newspaper quoted official documents and other sources.

The paper said an investigation lasting several months revealed that the June 16, 2017, meeting had been secretly recorded. Lauber lost his job after the discussion became publicly known.

Lauber's lawyer told the paper his client was not aware he had been spied on.

Lauber's office was at the time investigating massive corruption allegations within world football, including alleged irregularities in the vote to give Qatar the 2022 World Cup.

The prosecutor was forced to step down after it was revealed that he had met with Infantino three times. Lauber initially denied holding the meetings.

FIFA also looked into the meetings but an investigation found that Infantino, who said the conversations were "perfectly legal", had no case to answer.

- 'Project Matterhorn' -
The 2017 encounter was at the luxury Hotel Schweizerhof, which has been run by Qatari owners since 2009, in a conference room in the same corridor as the Qatari embassy, NZZ said.

The report added that Qatar sought to sway international opinion amid fears it risked losing the right to host the 2022 World Cup over allegations of corruption and human rights abuses.

With the help of former CIA agents, the country spied on FIFA officials and on Lauber, according to NZZ, which said it had obtained "official secret documents" on the hotel bugging.

The paper said sources with direct knowledge had described the operation, on condition of anonymity, and had said it carried the code name "Project Matterhorn".

The sources said the goal of the espionage was to gather incriminating material that could be used to pressure the prosecutor.

With the bugging campaign, Qatar would have been aware that the Swiss attorney general had provided untrue statements to his authorities when he maintained that no informal meetings took place with Infantino after 2016.

According to NZZ, Lauber's lawyer said the former attorney general had no knowledge of any bugging or recording of the Schweizerhof meeting, and had never been blackmailed or approached by Qatari operatives.

The Qatar government said it could take legal action over the reports.

"The allegations are another attempt to spread false information about Qatar and damage its reputation," said a statement released by the government's International Media Office.

"We reject the allegations and are exploring all legal avenues. It is evidently clear that the multiple smear campaigns against Qatar in Europe, revealed by media reports in France, Switzerland and elsewhere in Europe earlier this month, relentlessly persist."

Qatar said "reputable" media should "verify the authenticity of such groundless allegations before contributing to the spread of disinformation".