Guru Josh: Death By Suicide, Body Found By Manager

Guru Josh's manager thought he was picking up his client to take him to the airport Sunday morning ... but instead discovered the rave pioneer had committed suicide.

Sources close to Guru Josh tell TMZ ... he had been suffering from depression for some time and was feeling down over Christmas. We're told he decided to book a flight home to see his father.

Our sources say Guru Josh emailed his manager at 6 AM Sunday, asking him to come to his place at 11 AM. We're told when the manager arrived ... he discovered Josh's body.

We're told the family is at the mortuary now, taking care of burial arrangements.