Spanish online newspaper published alleged court documents on Friday, which named De Gea and Athletic Bilbao forward Iker Muniain in relation to an ongoing case involving pornography businessman Ignacio Allende Fernandez better known as 'Torbe' who ran a child prostitution ring.
'Torbe' was arrested in April after being accused of running a child prostitution ring. A witness in the case is claiming that it was the goalkeeper who set-up a date between her, one other girl, and two Spanish Under-21 players in 2012.
At the date set-up by De Gea, the woman said she was sexually abused by the two footballers at five-star hotel in Madrid.
The two players alleged to have abused the woman are Atletico de Bilbao forward Iker Muniain but the other football star could not be indentified.
According to Eldiario.es investigators are treating the witness's information with a 'great deal of credibility'.
She is said to have claimed Torbe took her to the sex date at a suite in the hotel where she met the footballers and another woman - and was ordered to 'do whatever they wanted'.
She was then warned to keep her mouth shut about what had happened. The newspaper also said the money she had been promised never materialised.
However, De Gea has denied having any involvement and insisted he would remain part of Spain's Euro 2016 plans after instructing his lawyers to handle the case.
"Firstly, I have to say I am the first surprised with this news," De Gea told a news conference. "I just want to deny everything, it is a big lie and falsehood. That's all.
"This is in my lawyer's hands. I am very, very calm. Everything is false and I don't have so much to say about this.
"I don't know where it is coming from. I am very calm, I know it is false."
When asked if he would remain at the tournament, De Gea replied: "Of course. It makes me even stronger to stay in the national team, having my team-mates' support too.
"I am looking forward to play this Euro and as I said before, everything which is on papers is totally false. It will be in my lawyer's hands."
Muniain also released a statement through his official Twitter account, in which he also denied the allegations.
He posted: "After the news reported today about myself, I would like to express:"1) The facts related are absolutely false.
"2) I will hand this matter to my lawyers in the coming days.
"3) I hope every fan who supported me on the pitch trusts me in this moment."