ETF Securities said on Tuesday the amount of metal it held to back its Physical Platinum exchange traded commodity fell 10 percent in the week to Aug. 24.
However, both the company's Physical Gold and Silver ETCs edged up to new records in the same week, as interest in bullion remained resilient.
The platinum ETC now holds 196,190 ounces of metal, its lowest level since Feb. 3 and down 22,000 ounces week-on-week.
The vehicle's holdings of the precious metal have slipped by more than a third over the last two weeks as spot platinum prices XPT= have fallen.
Holdings of its Physical Palladium ETC dipped 4 percent in the same week to 211,164 ounces, although its Physical Gold and Physical Sivler ETCs rose to new all-time highs.
The company added 54,000 ounces or 3 percent to its gold ETC, whose holdings now stand at a record 1.854 million ounces. Its silver ETC also reached a new all time high of 10.56 million ounces, up 8 percent week-on-week.