The Football Association is investigating whether banned midfielder Sandro Tonali breached betting rules after joining Newcastle in the summer.
Tonali, 23, was suspended for 10 months by the Italian Football Federation in October for betting on matches involving his teams Brescia and Milan.
The ban was made worldwide.
He joined Newcastle from Milan for £55m in July and the FA is investigating whether he was involved in betting on football following that move.
Meanwhile, Magpies sporting director Dan Ashworth said he did not know if Milan were aware of the betting charges when they sold him.
“It’s really difficult for me to get into what other clubs do or don’t know,” Ashworth said.
“All we can do is look at our own internal investigation and internal process. It’s a really difficult question for me to answer – I just don’t know.
“It was a massive shock, a massive surprise. Dealing with it was new to all of us. It came from nowhere.”
In reply, Milan told the BBC they first learned about the charges from the media and only know what has been reported in the news.
Tonali only made 12 appearances for Eddie Howe’s side before the implementation of the ban, which will keep the Italy international out until the start of next season.
The federal prosecutor and Tonali agreed a plea bargain, meaning eight months of his ban will be commuted to “a therapeutic plan” to help “recovery from gambling addiction”.
That will include Tonali making at least 16 public appearances in Italy, where he will be expected to speak to young players about the dangers of gambling.
Though unable to play in any matches, Tonali can train alongside his Newcastle team-mates during his ban.