Two weeks ago, Bayern's director of sport, Max Eberl, had been told the Premier League champions have no intention of selling Diaz and will not enter into discussions for the attacker.
Bayern’s bid was rejected, and the deal seemed to be off between the two sides.
However, the Bundesliga champions have submitted a proposal worth €67.5 million (just shy of £60m) on Tuesday morning, according to transfer guru Fabrizio Romano, who says the Reds took no time in turning the offer down.
"Liverpool have received an official bid of €67.5m from FC Bayern for Luis Diaz this week," he said on social media.
"The club rejected the proposal, and it was turned down after Liverpool had already closed doors to approaches in June," he added, citing The Athletic, claiming both Bayern and Barcelona are interested.
David Ornstein, of The Athletic, also revealed Diaz has made clear he wants to leave Anfield.
Liverpool are adamant the Colombian international is not for sale at any price this summer, and their latest rejection is evidence of that.
It's hard to shy away from the fact that the tragic loss of Diogo Jota will make the club resistant to selling a player in a similar position, and manager Arne Slot may be keen to keep his attack together for the foreseeable future.
The Liverpool board have thrown their weight behind Slot after the Dutchman delivered the Premier League title in his first season as he's brought in Florian Wirtz, Milos Kerkez and Jeremie Frimpong.
However, despite such expensive incomings, Slot does not want to lose a high-quality player such as Diaz ahead of another title race, and it looks like the 28-year-old is set to stay, even if he is open to leaving.