The judge who made Katherine Jackson guardian for Paris Jackson has ordered an investigation into Paris' attempted suicide, to determine if her welfare has been compromised ... TMZ has learned.

Judge Mitchell Beckloff has asked an investigator in the probate court -- where the guardianship was established -- to "prepare a written report and include therein any recommendations relating to the minor child's health, education and welfare."

Judge Beckloff notes he was alerted to Paris' crisis by media reports.  As you know, TMZ broke the story ... Paris is under psychiatric evaluation after cutting her arm with a meat cleaver and downing a number of Motrin, in what authorities call a suicide attempt.

It's an interesting development ... because the judge seems to be concerned about the supervision and guidance Paris is getting from the people responsible for her care.