Former Kanye West collaborator Theophilus London has vanished without a trace, so says his family ... who's now pulling out all the stops to lock down his whereabouts.
Law enforcement sources tell TMZ Hip Hop that London's relatives filed a missing person report with the LAPD on Tuesday ... and cops are now investigating the situation.
According to London's family, the last time the Trinidad and Tobago-born artist was heard from was July. They said they flew into L.A. this week to file the police report.
"Theo, your Dad loves you, son," London's father said in a statement this week in the hopes of locating the 35-year-old. "We miss you. And all your friends and relatives are searching for you. Wherever you are send us some signal."
"No matter what we will come get you son."
London's family described Theophilus -- who was famously front and center in the creation of Kanye's "Donda" album -- as 6'2", 175 pounds, with dark brown eyes. Of course, his likeness can be found all over YouTube from the millions of views his music videos amassed over the years.
We’re told Theo’s cousin Mikhail Noel is leading the rescue party charge and fielding inquiries and updates.