More investigations 'may be required' in Sheku Bayoh case
Prosecutors say further investigations may still need to be carried out before they decide if criminal proceedings should be brought over the death of a man in police custody.
Sheku Bayoh died after being restrained by officers in Kirkcaldy in May 2015.
A police watchdog has now submitted a supplementary report to the Lord Advocate, but the Crown Office said "further work may be required".
Mr Bayoh's family want a public inquiry to be set up to investigate his death.
The Police Investigations and Review Commissioner (Pirc) has now provided a full report on the death of Sheku Bayoh to the Lord Advocate, James Wolffe QC.
Pirc submitted an initial report in August 2015, but has now made an extra submission relating to "additional lines of investigation" which came up during their inquiry.
Mr Bayoh died in police custody after being restrained by officers in Kirkcaldy, Fife, on 3 May 2015.
His family set up a campaign for answers amid fears race may have played a part in his death, and met the previous Lord Advocate, Frank Mulholland QC to discuss their concerns.
Mr Wolffe will consider the latest report, but the Crown Office warned that more work may yet need to be done.
A spokesman said: "The Pirc report will be carefully considered, but this is a complex investigation and further work may be required before any decision is made as to whether or not there should be any criminal proceedings.
"The family will continue to be kept informed of any significant developments."
Aamer Anwar, a solicitor representing Mr Bayoh's family, said their "confidence in the robustness and impartiality" of the probe had been "shattered".
He added: "The Bayoh family hope that they can maintain confidence in the new Lord Advocate to ensure all necessary further enquiries are completed by Crown Office before any conclusion is reached on what happens next. We understand that this process is likely to take some time.
"Whilst the family await the Lord Advocate's decision on the appropriate way to proceed, they believe there is still a need for fundamental reform of Pirc so that no family who loses a loved one through a death in custody is forced to set up a campaign simply to get answers.
"As a result the Bayoh family maintain their call for a public inquiry to be set up into the death in custody of Sheku Bayoh and into the wider issues raised surrounding police accountability in Scotland."
Police have previously dismissed suggestions of racism surrounding the case. Mr Mulholland confirmed that a fatal accident inquiry will be held into the case, regardless of any criminal proceedings.
A spokesman for Pirc said: "The Commissioner appreciates that this has been a difficult period for the family of Mr Bayoh whilst this complex and wide ranging investigation has continued.
"A significant part of the work involved the gathering of expert evidence from a range of specialist forensic pathologists to give a greater understanding as to the cause of Mr Bayoh's death.
"During the enquiry additional lines of investigation emerged which have lengthened the process. The Commissioner ensured that all of the matters raised were rigorously explored so that the Lord Advocate is presented with a comprehensive report in order that he can make informed decisions on further action.
"The Commissioner considered it was important that the quality of the investigation was not compromised by speed."