A beverage company in Beijing was found to have marked its products with fake production dates, Beijing News reported on Thursday.

Two reporters from the newspaper disguised themselves as workers and entered a factory of Xibaolu Beverage Co in suburban Huairou district on Dec 21 to investigate after getting reports from consumers, Beijing News said.

The reporters found cans of a walnut and peanut beverage produced that day were printed with dates of Jan 1 or 2, 2013. A total of 166,719 cans of this beverage were printed with the wrong dates, according to the report.

A worker with the company told the reporters that they marked the products with future dates to meet the high demand in case a batch of the beverage sold out. Another worker said the printing machine can be adjusted so production dates can be revised.

Using fake production dates or revising the date can result in a fine from 500 to 10,000 yuan ($80 to $1,600), and heavier penalties apply for cases causing consequences, according to the regulation on food marking management.