Serge Gnabry was Germany's top scorer at the Olympic Games. EVARISTO SA/AFP/Getty Images

Serge Gnabry's transfer to Werder Bremen from Arsenal is unconventional, according to a member of the German club's supervisory board amid persistent reports Bayern Munich have some involvement in the deal.

Gnabry, 21, was initially expected to join Bayern Munich before being loaned out to Bremen for the season, but he ended up moving directly to Bremen for a fee in the region of €5-6 million.

Kicker reports that Bayern paid the transfer fee on behalf of Bremen in order to secure an option to buy the player, though ESPN FC sources indicated that Bremen paid the fee themselves. Meanwhile, Syker Kreiszeitung, a well-informed local paper, report that a release clause in Gnabry's contract would enable him to leave for Bayern before it ends.

Willi Lemke, who served as Bremen's general manager for 18 years and is now on the club's supervisory board, told Sport1's Doppelpass show on Sunday that Gnabry's transfer was not conventional.

"I think it's really very clever and creative how Frank Baumann [Bremen general manager] has gone about the deal," he said. "I think it's great how it's turned out.

"It's difficult for me to talk openly about it as I'm a member of the supervisory board and have to adhere to confidentiality."

ESPN FC's German football expert Raphael Honigstein also appeared on the show and suggested that it was a win-win situation for both Bundesliga clubs: "Bremen have been helped out a little by Bayern. If Bayern had inquired about Gnabry, they would have been quoted a much higher price. If Bremen asks they can say that 'we can't afford any more than €5m.'

"There is no agreement with Bayern, but if there's a need, they can sign him if they want to."

Baumann again strongly denied Bayern's involvement on Sunday to Weser Kurier, while Bayern are yet to officially comment on the ongoing speculation.

Information from Bayern correspondent Mark Lovell was used in this report.