Williams's date of death was estimated to have been in the early hours of 16 August, one week before he was found. Soon after the investigation started, the heads of the Secret Intelligence Service and Metropolitan Police met to discuss how the police would handle the investigation in light of the top secret nature of Williams's work, and who would lead the investigation. Williams had recently qualified for operational deployment, and had worked with U.S.
National Security Agency and
FBI agents. The
U.S. State Department asked that no details of Williams's work should emerge at the inquest. The foreign secretary,
William Hague, signed a
public-interest immunity certificate authorising the withholding from the inquest of details of Williams's work and U.S. joint operations. After launching an investigation, coroner Fiona Wilcox said that there were no injuries on his body and no signs that he had been involved in a struggle; his body was also free of alcohol and common recreational drugs. The
Metropolitan Police considered his death "suspicious and unexplained". The FBI also conducted their own investigation into the case. In December 2010, police released further details, stating that Williams had occasionally spent between 30 minutes and an hour on
bondage websites, but added there was no evidence that he was "obsessed" with bondage and no other pornography was found. Williams's wardrobe included £25,000 of "high-end" women's clothing. The landlady of the annex flat he had rented in Cheltenham for 10 years said she and her husband had once found him, three years before his death, shouting for help, with his hands tied to his bedposts. He said he was seeing if he could get free. They cut him free, believing it was "sexual rather than
escapology". An expert brought in to examine the bag in which Williams's body was found concluded that Williams could not have locked it. A police spokesperson stated that "If he was alive, he got into it voluntarily or, if not, he was unconscious and placed in the bag." The heating in Williams's apartment was found to be turned on. Subsequently, the police released an
E-FIT photo of two people they were seeking, who were seen to enter the communal entrance of his home in June or July 2010. ==Coroner's inquest==