In a dramatic twist at the inquest into the death of 20-year-old Lakhvinder "Ricky" Reel, John Bevan QC, for the police, claimed the last people known to have seen him alive were coerced into exaggerating a racial incident that occurred minutes before his disappearance.
Michael Mansfield QC, for the Reel family, said that the claim was a "reprehensible" attempt by the police to play down a racial incident.
The case has been a source of acute embarrassment to the London force as it tries to repair its reputation following the Stephen Lawrence inquiry.
Mr Reel was out with three friends on the night of 14 October 1997 when they were attacked by white youths in Kingston upon Thames, Surrey. They scattered and when they regrouped, Mr Reel was missing. His body was pulled from the river Thames a week later.
An initial Metropolitan police investigation dismissed his death as an accident, saying the young man, from West Drayton, had fallen into the river while trying to urinate.
His family, however, remain convinced his death was linked to the earlier racial attack. They have fought tirelessly for "Justice for Ricky", supported by the Southall Monitoring Group,(SMG) which campaigns to highlight racial injustice.
Mr Bevan told the West London Coroners' Court that the head of SMG, Suresh Grover, had coerced the young men - known only in court by the nicknames Dave, Manny and Brett - into exaggerating the racial incident.
Mr Bevan quoted one linefrom a letter the three wrote to Mr Grover in November 1997: "This letter endeavours to put forth to you [our] opinions and feelings without them being repressed and even coerced [sic] into changing [our] views."
Mr Grover said: "It is a serious allegation that he was coercing them into changing their views...
"Somebody has tried to coerce them into changing their views, into making it seem like it was a much more serious racial incident than it was."
Mr Mansfield replied: "None of the boys have suggested they changed their accounts."
The inquest continues.