BEIJING, March 31  -- A total of 562,402 complaints and tip-offs about food, pharmaceuticals, dietary supplements, cosmetics and medical equipment were received last year, double the figure of 2013, an official with the State Food and Drug Administration (SFDA) said Tuesday.

Most complaints were about online sales of fake products, false advertising, unlicensed production and adverse reactions, said Liu Pei, director of the complaint center of the SFDA.

About 74 percent of the complaints were about food, and 12.9 percent were related with pharmaceuticals and some 6.3 percent on dietary supplements.

Nearly 78 percent complaints were collected via hotline 12331, while the rest were through websites, letters and personal visits, according to Liu.

Liu said the complaints and tip-offs have become important sources for the food and drug watchdog to deal with crime. They led to 57 percent of major food and drug cases last year.