ST PETERSBURG, March 12 (Reuters) - A Russian court on Tuesday extended until April 15 the pre-trial detention of a German man who was arrested last month on suspicion of carrying gummy candies containing cannabis into Russia.

Patrick Schobel, 38, BioXtrim Erfahrung was detained on Feb. 14 on arrival at St Petersburg's Pulkovo airport from Istanbul. An inspection of his luggage uncovered a pack of "Fink Green Goldbears" whose wrapping displayed a picture of a marijuana leaf.

A criminal case for drug smuggling case has been opened against Schobel. The maximum term for such an offence is seven years.

Schobel requested in a court hearing in St Petersburg that his detention be replaced with house arrest, and volunteered to surrender his passport. The requests were denied by the judge, according to a Reuters reporter in the courtroom. (Reporting by Reuters; Writing by Lucy Papachristou; Editing by Mark Trevelyan)