The unsolved assassination of a key witness who helped to put road-rage killer Kenneth Noye behind bars remains under investigation by detectives, police have said.
Noye, who was jailed for stabbing to death 21-year-old Stephen Cameron during an altercation on the M25 in 1996, was questioned over Decabral’s shooting but was not charged.
Kent Police also investigated whether Decabral had been caught up in a war between rival biker gangs fighting over lucrative drug trade.
His killer has never been caught despite a large manhunt.
Noye, 71, will be released from prison later this year after the Parole Board said last week he no longer posed an unmanageable risk to the public and was “suitable for return to the community’’.
He was sentenced to a minimum of 16 years behind bars for killing Cameron with a nine-inch kitchen knife near Swanley.
Noye went on the run following the electrician's murder but was arrested in Spain in 1999 after Cameron’s girlfriend, who had witnessed the stabbing, was flown out by police to identify him.
At his April 2000 trial, Decabral told London's Old Bailey he had seen two men fighting on a motorway slip road. He told the jury he saw Noye “lunging forward” with a knife and stabbing Cameron.
Decabral was shot dead in front of shoppers through the open window of his car at a retail park in Ashford on 5 October.
Witnesses to the murder said they heard the father-of-three beg for his life before she was shot dead by a young man wearing a woolly hat.
Decabral was a career criminal with links to drugs, firearms dealing, and alcohol and tobacco smuggling.
During Noye’s trial, defence lawyers maintained Decabral was an unreliable witness who created an “edifice of lies” as a bargaining tool with police.
At an appeal hearing in 2001, Noye’s barrister Michael Mansfield said he "was alive to the fact the police had an interest in him".
He added: “As a result of his criminality and vulnerability he had a motive to lie in 1996 when giving his statement – he had a bargaining tool. In his 999 call he claimed he had seen a gun – there was no gun.”
A Kent Police spokesperson said this week: “Alan Decabral, aged 40, of Pluckley, was murdered in October 2000. To date, there have been no charges in relation to his death. The file on this case remains open and, as with all unsolved major crimes, Kent Police regularly review cases.”