There has recently been a host of speculation surrounding the right-back's contract, with Manchester United also believed to be keen on his signature this summer.
However, West Ham are seemingly at the head of the queue, and according to Sky Deutschland, the London club have now reached an agreement with Bayern over the Morocco international's signature.
The fee is allegedly €16m (£13.5m) plus €3.5m (£3m) in performance-related add-ons.
The 26-year-old made the move to Allianz Arena from Ajax in the summer of 2022, and he has represented his current side on 55 occasions in all competitions.
Last season, Mazraoui made 29 appearances for Bayern, including 19 outings in the Bundesliga.
Sessegnon 'closing in' on Fulham return
Meanwhile, according to BBC Sport, Ryan Sessegnon is closing in on a return to Fulham on a free transfer.
The left-back left Tottenham Hotspur when his contract expired at the end of June, having found it difficult to overcome a whole host of fitness problems.
However, Sessegnon is now allegedly close to rejoining Fulham, with the 24-year-old set to undergo a medical ahead of signing a two-year contract with the option for another season.
Sessegnon had been on trial at Crystal Palace, but he is now preparing to return to Craven Cottage.
The defender made 120 appearances during his first spell at Fulham, including 35 outings during the team's 2018-19 Premier League campaign.
Meanwhile, he has left Spurs with a record of three goals and four assists in 57 appearances in all competitions.
Leicester youngster 'heading' for Wigan
Elsewhere, Wigan Athletic have allegedly won the race to sign highly-rated Leicester City attacker Silko Thomas on loan for the 2024-25 campaign.
A number of clubs have allegedly expressed an interest in signing the 20-year-old this summer.
However, according to Football Insider, Wigan are close to securing his signature on a short-term basis.
The report claims that clubs in the Championship have been in touch with Leicester, but the Foxes believe that a season in League One would be more beneficial.
Thomas was in the Chelsea academy between 2014 and 2023 before moving to the King Power Stadium, and he has a record of five goals and four assists in 16 appearances for Leicester Under-23s in Premier League 2.