David McKie, 63, was stabbed on Tuesday night two miles from the Whitechapel flat where Barry Stubbings, a City stockbroker, was found murdered a few hours later.
Scotland Yard said that a man had walked into a London police station yesterday morning with his solicitor after police announced that they were linking the attack on Mr McKie with Mr Stubbings' murder.
The two attacks sparked fears that a potential serial killer was stalking London's gay community only months after Colin Ireland was jailed for life after killing five gay men. But yesterday police said the two attacks were not now thought to be linked.
Mr McKie, who is still undergoing treatment at the Royal London Hospital, suffered neck, chest and hand wounds during the attack at his 10th floor flat in Prusom Street, Wapping, at about 7.30pm on Tuesday, shortly before Mr Stubbings, a director with the City broking firm James Capel, was last seen alive.
Police said on Friday they were exploring links between the two incidents. Detective Superintendent Albert Patrick suggested that the attack on Mr McKie could be 'crucial' to discovering who murdered Mr Stubbings.
Like 51-year-old Mr Stubbings, police believe Mr McKie was homosexual. He admitted a man to his flat shortly after which neighbours heard shouting then cries for help.
Detectives believe that Mr Stubbings returned to his flat with his killer last Tuesday. His partly-clothed body was found when police broke into the flat the following day after the dead man's colleagues alerted them when he missed appointments at work.
Mr Stubbings' body was found in the living room. His throat had been cut. Police believe his killer searched the flat thoroughly but do not yet know whether anything had been stolen.
The dead man was a director of corporate finance for stockbrokers James Capel. He joined the company 33 years ago as a 17-year-old and worked his way up the ranks to his pounds 150,000-a-year post.
He had a reputation as a 'workaholic' often beginning early and working late into the night. Det Supt Patrick did not rule out the possibility that his murder was connected with his work. Staff at the firm are being interviewed by detectives.
The company described Mr Stubbings as a 'dedicated and consummate professional who was highly respected by all who knew and worked with him'.
But police have discovered very few of his colleagues knew anything of his private life beyond that he would visit his 88-year-old mother near Ashford in Kent most weekends and was fond of gardening. Mrs Ena Stubbings was being comforted by her second son Michael this weekend. She has not been told the full circumstances of his death.
Police have established the dead man lived what they described as a 'double life' visiting gay pubs and clubs and picking up strangers at public lavatories. Mr Patrick said he was known to have used at least two aliases - 'Tony' and 'Peter'.
Two men have already come forward and told police they were having a relationship with him. One had been going for two years while another was more recent.
Police have appealed for others who knew the dead man to come forward. Police are questioning restaurateurs and owners of gay venues in an attempt to establish the dead man's last hours.
Mr Patrick said Mr Stubbings had had a Chinese or Indian meal shortly before his death. Neighbours at his flat heard two people enter at about midnight on Tuesday and somebody leave approximately three hours later.
Detectives appealed for information about a man seen near Mr Stubbings' flat in Whites Row around midnight on Tuesday.
He is described as white, of average build and about 5ft 8ins tall. He was wearing dark clothing, possibly a suit, and may have had a beard.
Mr Patrick said yesterday he was anxious not to cause alarm in the gay community but said police had been criticised in the Colin Ireland case for not passing on information quickly enough.
'The gay community has been warned,' he said, appealing for people who knew the dead man or who may have seen him on the night of his murder to come forward.
Police yesterday took large amounts of the dead man's professional and personal correspondence away from the flat.
Mr Stubbings was said to have kept 'meticulous records' and police are scrutinising them in the hope they will yield clues to his killer.