On Monday afternoon, reports emerged that police had responded to the accusation of rape at The Bank Hotel where Mbappe stayed during a stay in Stockholm last week.
In light of the investigation, the 25-year-old took to social media to describe the development as "fake news", claiming that it was "predictable" ahead of an upcoming legal case against Paris Saint-Germain over alleged unpaid bonuses to the total of £46m.
However, according to local outlet Expressen, it is Mbappe who is at the centre of the investigation for an incident that allegedly took place on Thursday.
The report claims that Mbappe is 'reasonably suspected' of rape and sexual molestation, the police having been contacted two days after the alleged incident.
Mbappe is said to have visited restaurant Chez Jolie and the nightclub V the following day prior to leaving Stockholm.
Prosecutor, Mbappe's entourage comment on development
As quoted by the same outlet, prosecutor Marina Chirakova said: "I will not confirm that it is a case of rape. The only thing I can say is that a crime was reported on October 10 in central Stockholm.
Meanwhile, Mbappe's entourage has released a statement to condemn the development, staunchly defending what they describe as a "new defamatory rumour".
Speaking to AFP, they said: "These allegations are completely false and their dissemination is unacceptable."
"To put an end to this methodical destruction of Kylian Mbappe's image, all necessary legal measures will be taken to restore the truth and prosecute any person or media involved in the harassment and defamatory treatment that Kylian Mbappe has repeatedly been subjected to."
What next?
From Real Madrid's perspective, the current hope is that Mbappe will be in a position to feature during their upcoming fixtures against Celta Vigo, Borussia Dortmund and Barcelona.
However, a thigh injury prevented Mbappe from representing France in their UEFA Nations League fixtures against Israel and Belgium during the international break.
Much may now depend on how legal proceedings against Mbappe develop over the coming days.