The Privy Council has recently corrected any impression that may have existed about when unreasonable delay should result in the staying of proceedings or the quashing of a conviction: Tapper v DPP (Jamaica) [2012] UKPC 26 (17 July 2012).
The quashing of a conviction is only appropriate where delay prevents a fair trial or where delay makes it unfair to put the defendant on trial at all: Boolell v The State (Mauritius) [2006] UKPC 46 (noted here on 18 October 2006).
Other remedies may be the reduction of a sentence or if the defendant is acquitted the payment of compensation, the making of a public apology, or the expediting of a trial without further delay: Attorney-General's Reference No 2 of 2001 [2003] UKHL 68 per Lord Bingham at [24]-[25], applied in Tapper.