Police Scotland are investigating but the death is not being treated as suspicious.
Sheku Bayo Family Plan Civil Action Against Police
A lawyer representing the family of a man who died in custody has said they intend to launch a civil action against Police Scotland.
Sheku Bayoh, 31, died after being restrained by officers responding to a call in Kirkcaldy, Fife, on May 3 2015.
A BBC documentary following his family's quest for answers is to be screened on Tuesday.
The Police Investigations and Review Commissioner (Pirc) has submitted a report on Mr Bayoh's death to Lord Advocate James Wolffe.
Lawyer Aamer Anwar said: ''Sadly Sheku Bayoh's family lost confidence many months ago in the Pirc delivering an 'impartial' investigation, however they still await the outcome of the robust inquiries being carried out by the Lord Advocate's team and nobody should prejudge their outcome.
''But the family have now instructed the launch of a potential civil action. They remain determined to seek out the truth without which they know there can never be justice.
''Sheku's death in police custody over 20 months ago revealed a 'worrying lack of accountability and flawed procedures' and his family believe that cannot be allowed to continue.''
A statement from the force said: ''Police Scotland has been committed to co-operating with the Pirc and the Crown Office throughout the investigative process.
''Our condolences remain with Sheku Bayoh's family and friends, and we continue to offer support to all those involved in or affected by this tragic incident.
''As we have previously stated, we cannot comment on the events of May 3 2015 while the Crown evaluates the independent findings submitted by Pirc.''
The Crown Office said: ``The Pirc report has been carefully considered.
''The Crown requires to undertake further work before a decision can be made as to whether or not there should be any criminal proceedings. That work is in hand.
''We will continue to liaise with the nearest relatives of the deceased's family to ensure that they are kept fully informed of the progress of the investigation.
''This is a complex investigation and a decision on further proceedings will be made as quickly as possible.''
The crash happened on the A92 in Fife at about 4.30am on Monday.
Chemicals found in cigarette smoke have been shown to damage foetal liver cells, but they affect boys and girls differently.
The SNP leader is hoping to build on her party's 2015 success of winning a record 56 out of 59 Scottish Westminster seats.
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