Paris Saint-Germain star Kylian Mbappe admits the amount of money involved in the highest level of football has become "indecent".

The 19-year-old became the second most expensive player in history when he completed a permanent transfer to PSG from Monaco this year for a reported fee of €180million.

His team-mate Neymar joined from Barcelona in 2017 for €222m in a deal that shook the European game and led to four more deals worth more than €100m, including Mbappe's taking place over the next 12 months.

Reports based on documents from whistleblowing platform Football Leaks this month claimed Mbappe asked for a five-year contract worth close to €55m after tax when he joined PSG, along with various performance-based incentives, which was turned down by the club.

And Mbappe has conceded there are sums involved in the top tiers of the game that he could scarcely have imagined when he was growing up.

"It's truly indecent for me, who comes from a fairly modest family," he told RTS.

"It's true that it's indecent but the market is like that. The world of football works like that.

"I'm not going to revolutionise football. I'm in a system. You have to know how to respect it and to stay in place."

Mbappe has been compared to Brazil great Pele following a remarkable rise to stardom during the last three years, in which he has won four major trophies in France and the World Cup.

However, the forward insists he is not trying to emulate anyone, saying: "I don't want to be a copy of anyone else. Like the greats, you want to make your own story yourself, and not be a copy of another.

"I think it's only natural to have high self-esteem, even if in everyday life you need to have that humility that is a strength of the greats."

Despite his spectacular career at senior level to date, Mbappe says it is important to retain a childish sense of humour.

"There is no bad time to laugh. I always joke, even five minutes before a game. It's not bad to stay a little immature," he added.

"There is so much pressure in football that a little bit of 'joie de vivre', a little bit of fun doesn't hurt in this environment."