The 19-year-old Ivorian enjoyed a spectacular debut season in Germany, scoring 13 goals and providing 10 assists in 36 appearances across the Bundesliga and German Cup. That form has carried over into the World Cup, where he was one of the standout performers on the opening matchday as Ivory Coast beat Ecuador.
Leipzig have already rejected an opening offer from Liverpool worth around €100m, with the Merseyside club reportedly prepared to return with an improved bid.
According to Bild, PSG are now in talks with Diomande's entourage to assess a possible move this summer, with the French club said to have been in contact with his representatives for several weeks to gauge his thinking. Leipzig's intention is to keep the winger for at least one more season, though the same report suggests the club is aware that will be difficult to achieve.
The scale of interest suggests Diomande could end up as the most expensive transfer of the summer, with Leipzig believed to be holding out for a fee close to €150m, an astronomical figure for a teenager with only a single senior season behind him.
With two of European football's wealthiest clubs now directly involved, all signs point toward one of the most expensive transfers in the sport's history.
Diomande's breakout campaign has drawn comparisons to some of the most explosive wing debuts in recent Bundesliga history, with his combination of pace, direct dribbling and end product making him an immediate fit for either Liverpool's high-tempo attack under Andoni Iraola or PSG's possession-based system.
RB Leipzig's resistance to selling reflects both the player's importance to the club's own ambitions and an awareness that his value is unlikely to ever be higher than it is right now, fresh off a World Cup performance that has only intensified the bidding.