Quick Google search yielded this :

"Mr. Moto was a mild-mannered, Japanese detective that was the basis for a series of eight films (1937-39) by Twentieth Century-Fox from the stories of novelist John P. Marquand. Peter Lorre portrays Kentaro Moto (I.A. Moto in Marquand's novels), who was very much unlike Charlie Chan in that he was the master of disguises and physically more active, often using ju-jistsu."

I remember those films and I loved them ... but remember I was only 10-years-old!!