By Brenda Goh and Norihiko Shirouzu
SHANGHAI/BEIJING (Reuters) - A Chinese man suing Tesla Motors Inc <TSLA.O> after his son was killed while driving one of the U.S. car makers' vehicles argues that the responsiveness of the car's "autopilot" function was responsible for the accident, his lawyer said.
Tesla's Autopilot, introduced in October, has been the focus of intense scrutiny. The company said earlier this month that it was updating the system with new limits on hands-off driving and other improvements that would help prevent fatalities.
The lawsuit in China would be the first involving the autopilot's role in a crash though there have been other fatalities elsewhere involving the function, the lawyer said.
Gao Jubin's 23-year-old son, Gao Yaning, died in January after crashing into the back of a road-sweeping vehicle while driving the car on a highway in the northeastern province of Hebei, according to a police report provided by the father's lawyer, Wang Beibei.
The family believes the car - a Tesla Model S sedan, according to the lawsuit - was driving in autopilot mode, the lawyer said. He said they had examined dashboard video footage and sought expert and other Tesla drivers' opinions.
"The autopilot programme's slow response failed to accurately gauge the road conditions ahead and provide instructions," according to lawsuit documents seen by Reuters.
Tesla said in a statement it was investigating the cause of the crash, but has "no way of knowing" if its semi-automated autopilot system was engaged at the time of the accident.
"Because of the damage caused by the collision, the car was physically incapable of transmitting log data to our servers," Tesla said.
Tesla issued the statement after Chinese state broadcaster CCTV on Wednesday reported on the accident. A dashboard video shown on CCTV showed Gao's white Tesla cruising on a highway in clear weather before crashing into the back of a cleaning vehicle.
CCTV quoted road police as saying the car did not brake before crashing into the vehicle.
Gao's lawyer said Tesla had been in contact after they filed the lawsuit in a Beijing court in July, but they had yet to reach agreement with the company.
Tesla, in its statement, said it had "tried repeatedly to work with" Gao's family to determine the cause of the crash, but the family "has not provided us with any additional information that would allow us to do so."
The lawyer said Gao disputed the claim.
"The car is still there, and the data can still be extracted. A consumer can't read the data, but Tesla could read the data," he said.
The case has also been filed against the Beijing-based dealer who sold the car.
Gao wants Tesla to pay him 10,000 yuan ($1,499) and his legal costs, and for the company and its Beijing authorized dealer to jointly admit responsibility, according to the lawsuit documents.
The family initially sued Tesla for 1 yuan to raise public attention, but increased their compensation demands later.
(Reporting by Brenda Goh in SHANGHAI and Norihiko Shirouzu in BEIJING; Additional reporting by Paul Lienert in DETROIT; Editing by David Gregorio and Christopher Cushing)