This file photo shows a technician inspecting a discarded Hewlett-Packard (HP) laptop computer. China's product-quality watchdog said US computer maker HP violated Chinese consumer rights rules, after an investigation into complaints about faulty laptops from dozens of customers.

China's product-quality watchdog said US computer maker Hewlett-Packard violated Chinese consumer rights rules, after an investigation into complaints about faulty laptops from dozens of customers.

The General Administration for Quality Supervision, Inspection and Quarantine has ordered HP to "strictly abide by" Chinese rules concerning repair, replacement and return of faulty products.

The agency said HP failed to deal with customer complaints in accordance with the rules and it "has to improve after-sales service and address quality problems in some of its laptops responsibly", according to the statement posted on its website Thursday.

The investigation found problems in a number of HP Pavilion DV2000 and Compaq Presario v3000 notebooks, which led to crashes, black screens and overheating.

Another six HP models were found to have defects in display screens, the statement said.

The statement came after the quality said on Sunday it was investigating complaints filed by 60 laptop users that certain HP computers were defective.

On Monday, HP issued an apology and extended the warranty for relevant laptops.