LONDON — A Jordanian princess who is married to the billionaire ruler of Dubai has for more than a year been discreetly working with British private investigators in an attempt to collect evidence of corruption in global soccer, according to several people with direct knowledge of the effort.

The princess, Haya bint al-Hussein, has hired Quest, a global advisory and investigations firm based in London, to help in her effort. The firm’s investigators have sought to meet with current and former FIFA officials, as well as scores of others from the often shadowy world of soccer politics. Quest officials also have been in contact with federal investigators in the United States, according to two of the people with direct knowledge of the investigation.

It is unclear what new information, if any, the investigators have uncovered, but the involvement of Princess Haya, whose brother Prince Ali bin al-Hussein was twice a losing candidate for the presidency of FIFA, soccer’s global governing body, suggests that while FIFA has claimed to have entered an era of reform since a corruption scandal toppled its leadership in 2015, its days of palace intrigue are far from over.

The investigation also raises the possibility that there may be more accusations of wrongdoing for a sport brought low by the series of indictments and arrests against top officials led by United States prosecutors in 2015. The United States case led to the fall of almost of all of FIFA’s top leadership, including its former president Sepp Blatter, who had defeated Prince Ali in an election in May 2015, only days after the Swiss police arrested several members of FIFA’s executive board at the request of the United States Department of Justice.