Patna, July 9 :     The city police have detected a new angle to the mysterious deaths of a political activist and a former beauty queen here last week. According to the police, Shilpi Jain and Gautam Singh died while making love in a locked air-conditioned car. ?It is a clear case of death due to asphyxiation. Gautam and Shilpi had sex in the car. While busy in their lovemaking, they failed to notice the symptoms of asphyxiation. Being an odourless and non-irritant gas, carbon monoxide brought about their slow deaths in the air-tight car,? said Patna city superintendent of police Manvinder Singh Bhatia. The investigation into the mysterious deaths of the leader of the youth wing of the ruling Rashtriya Janata Dal (RJD) and the former city beauty queen has come to an end with these findings by the investigating officers, Bhatia said. He added the police had taken the help of medical experts, motor engineers and doctors to arrive at this conclusion. Shilpi Jain and Gautam Singh were found dead inside a Maruti Zen in the wee hours of July 3 at the garage of Gautam?s home near Gandhi Maidan. While Gautam was naked, Shilpi had a T-shirt on at the time of her death. Semen was detected on her person. There was widespread speculation the couple had either committed suicide or had been murdered. Forensic experts said if a small percentage of carbon monoxide gets mixed with haemoglobin, it forms carboxyhaemoglobin, which is fatal. A victim may not realise its fatal impact even after inhaling a small concentration of the gas. It can gradually choke the heart, causing painless death. The police said Gautam had been in the habit of making love in his car with the windows locked. But he had never faced the threat of carbon monoxide poisoning before as he had previously used his Cielo. Bhatia said this car fulfils the Euro-1 emission norms, but the Maruti Zen does not. As a result, in the Maruti Zen, the possibility of asphyxiation for the couple, who had locked the car windows, was greater. The city SP said the autopsy reports have corroborated the theory of death due to asphyxiation by carbon monoxide.