Mark Grudzielanek — a former MLB All-Star and Gold Glove winner — has been accused of child abuse … and he’s now under police investigation.

Police documents show Grudzielanek is alleged to have committed the crime at around 10:30 PM on March 26 in Scottsdale, Ariz.

In the docs, Grudzielanek — a 50-year-old who played in the MLB from 1995 to 2010 — is listed as an “offender” … and the alleged victim is described as a 12-year-old boy.

Details of the alleged incident are unclear … but a source close to the case tells us the allegations stem from a physical altercation.

We’ve reached out to Grudzielanek for comment, but so far, no word back yet.

Grudzielanek broke into the Big Leagues in 1995 with the Expos … and he was named an All-Star the following year.

The infielder went on to play 15 seasons in the league … winning a Gold Glove in 2006 with the Kansas City Royals and posting a career batting average of .289.