Defects found in mattress products sold in Beijing have prompted the city's quality watchdog to investigate the furniture market.

Among the 25 defective mattresses reported by the Beijing Consumers Association, 13 were produced in Beijing.

Of those 13 manufacturers, eight did not register at commerce authorities, Beijing Municipal Administration of Quality and Technology Supervision said.

The administration has begun inspecting the other five enterprises about the products and raw materials they use.

Enterprises that make substandard products will be punished, it said.

The administration will carry out a comprehensive inspection on upholstered furniture including mattresses and sofas starting this month, instead of the third quarter this year, as originally planned.

It will release the inspection results to the public as soon as the work is completed.

Of the 50 mattress products tested at the National Center for Quality Supervision and Inspection of Furniture and Indoor Environment, 25 failed for reasons such as color fading, fabric use, toxic substances and durability, the Beijing Consumer Association said on Sunday.