Premier League players Sandro Tonali and Nicolò Zaniolo were sent back to their clubs from Italy's training camp on Thursday after being notified by police of involvement in a betting investigation.

The move comes a day after Juventus midfielder Nicolo Fagioli acknowledged that he is being investigated by Turin prosecutors in the same case for alleged betting online via unauthorized websites.

After police were seen at the national team's Coverciano training center to question the players, the Italian soccer federation announced that Tonali and Zaniolo had been handed official notifications of their involvement in the Turin inquiry.

"Regardless of the nature of the events, considering that the two players are not in the necessary condition to face the matches scheduled for the next few days, the federation has decided, also for their protection, to allow them to return to their respective clubs," the federation said in a statement.

Tonali is a midfielder with Newcastle -- having transferred from AC Milan in July -- and Zaniolo is an attacking midfielder at Aston Villa on loan from Galatasaray.

Italy host Malta on Saturday and then visit England three days later in European Championship qualifying.

Randal Kolo Muani, Ousmane Dembele, Achraf Hakimi and Layvin Kurzawa have been named as the four players who have been handed suspensions.