Detective Chief Inspector John Carnt, who is currently in charge of the investigation, told Southwark Coroner's Court in south London that the police received a call on 24 April 1993, with information that would lead them to recover the murder weapon.
"We were told to search a rubbish bin of a car park of a local public house for a knife. An officer went to the car park and searched the bins, but he found nothing. On his return a letter had been attached to the rear windscreen of his car naming four suspects."
He said the names were researched, which involved checking whether they had any previous criminal record or were known to the local police.
"They were not visited immediately as it was decided to conduct some further research, as after all it was anonymous information," he said.
Cross-examined by Michael Mansfield QC, for the Lawrence family, the detective conceded that the same names had been given by named sources from an early stage.
"On the 24th, 25th, 26th, 27th, you had both named and anonymous information and I want to suggest it was the same names coming in time and time again," Mr Mansfield said.
The detective agreed.
The names of the suspects were revealed to the jury, but the coroner, Sir Montague Levine, ordered that they could not be published.
Mr Lawrence was stabbed, apparently in a racist attack, as he waited for a bus in Eltham, south-east London, in April 1993.
Det Ch Insp Carnt told the court that it was two days before the police acted on the information and said the addresses of the suspects were visited only as part of a routine door-to-door inquiry.
The court heard that the police received the names of these suspects time and time again in the weeks following the murder.
Mr Mansfield said the police investigation into the brutal stabbing of the A-level student was "remiss in the extreme" and displayed a catalogue of lost opportunities.
The court was told there had been a number of racial assaults in the past and two murders in the area in the two years prior to the incident. But despite a history of problems a special racial incident office at Plumstead police station, which kept information on families under suspicion, remained closed while the search for suspects was carried out.
Mr Mansfield suggested the police had ignored the most simple of investigative techniques available to them.
Questioning Detective Inspector Philip Jeynes who was at the scene at the time of the investigation, Mr Mansfield said: "Besides getting evidence from the scene you would ask what used to be the local bobby who do you think is capable of an unprovoked racial attack? It was a remiss in the extreme not to get this information."
Det Insp Jeynes agreed to the suggestion that it would have been sensible to consult the criminal intelligence unit at Scotland Yard to find out if it had any information relating to families in the area who were under suspicion for racist activity.
Mr Mansfield asked why no one attempted to contact the Yard, to which the officer replied: "Because it was one o'clock in the morning and I had other things to consider."
Mr Mansfield added that had it been a police officer lying killed in the street information would have been passed on very quickly indeed.
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