Vitor Mendonca, 17-year-old, was reported missing by the force on Sunday February 12.
Taking to Twiter at 3.05pm, the police said: "Vitor MENDONCA aged 17yrs #missing from #Feltham, we really need your assistance to find Vitor.
"Call 101 ref 17MIS004745.
Anyone with information relating to the whereabouts of the teenager should call police on 101, stating the reference 17MIS004745.
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