China on Friday denied allegations that its operatives secretly copied the contents of a US government laptop computer and used the data to try to hack into Commerce Department computers. US authorities say they are investigating whether surreptitious copying took place when a laptop was left unattended during a visit to China by Commerce Secretary Carlos M. Gutierrez for trade talks last December. Shortly afterward, three serious attempts at data break-ins at the Commerce Department were reported, according to US officials. In Beijing's first comments on the allegations, Foreign Ministry spokesman Qin Gang said Chinese officials knew nothing about the laptop cited in the reports. He repeated China's claim that it too was a victim of cybercrime. “These reports are totally groundless,” Qin told reporters at a briefing for a new round of US-China trade talks later this month. The reported incident is the latest in a series of cybersecurity problems blamed on China.