An alleged serial killer accused of drugging and murdering four men he met on gay websites has been charged with attacking eight others. Stephen Port, 41, was originally charged with four counts of murder and four counts of administering a poison. He is also accused of six further counts of administering a poison, seven of rape and four sexual assaults against another eight men, it can be reported for the first time. He pleaded not guilty to all the charges, which allegedly took place between 2011 and 2015, at the Old Bailey on Monday. Port, of Barking, east London, sat with his hands clasped in front of him as each of the charges was read out in court. Appearing in court via video-link from Belmarsh Prison, wearing smart black trousers and a light shirt, he spoke only to confirm his name and enter pleas during the brief hearing. Four of Stephen Port's alleged victims suffered overdoses and were dumped in or near a churchyard in east London CREDIT: FACEBOOK Port also faces four alternative charges of manslaughter for each of the murder counts, which he also denies. He allegedly met the men on gay websites and invited them to his house, where he is accused of poisoning them with the party drug GHB. Four of his alleged victims, all in their 20s, suffered overdoses and were dumped in or near a churchyard in east London. Port is due to stand trial on October 4, with his case expected to last up to 10 weeks. Detectives began an investigation after four men died over a period of 14 months. Anthony Walgate, Daniel Whitworth and Jack Taylor CREDIT: FACEBOOK The first, Anthony Walgate, 23, was found dead on June 19, 2014. He was a fashion and design student at Middlesex University, and was originally from Hull but living in Barnet. Gabriel Kovari, 22, was found by a dog walker near a churchyard on August 28, 2014. He was originally from Slovakia, but lived in Lewisham, south London. Just under a month later, on September 20, 2014, the same dog walker discovered the body of Daniel Whitworth, 21, from Gravesend, Kent, near the same churchyard. Then on September 14 last year, Jack Taylor, 25, a forklift truck driver from Dagenham, was found dead near the ruins of Barking Abbey. Man accused of poison murders arrives in courtPlay!00:55 The deaths were not initially linked but after further investigation they were referred to the Metropolitan Police homicide and major crime command on October 14 last year. The force has referred its handling of the case to the Independent Police Complaints Commission (IPCC).