A News of the World surveillance team jeopardised the investigation into the Ipswich murders, a retired criminal investigator has claimed.Dave Harrison, who was part of the Serious Organised Crime Agency team working on the 2006 investigation, told the Leveson Inquiry he was told a surveillance team had been deployed by the newspaper to find out who the SOCA team where and where they were based.Five women were murdered by Steven Wright, a local man, between October and December 2006. Due to the size of the investigation other officers, including Harrison, were drafted in to assist Suffolk Police.He told the inquiry: "We identified them because they were sat in the positions that we would sit in if we were doing the same job... If they knew nothing about surveillance, they wouldn't have got anywhere near us."The former investigator said the News of the World team could have seriously hampered the investigation, as murder suspects often return to the scene of the crime to remove evidence, or commit further offences. He said a suspect being aware they were being followed, either by police or the press, would not behave in this way, damaging the chance of a successful prosecution.Surveillance would also have been weakened as the SOCA team tried to avoid being followed by the press team.Harrison said a similar team from the Sunday Mirror had picked up the first suspect of the murders, who was later cleared, and debriefed him in cars before taking him to be interviewed.He told the inquiry they had also used "anti-surveillance capabilities" to elude the investigators.