https://thuraisingam.com/resources/the-extent-of-an-accused-persons-right-to-statements-and-disclosure-of-evidence-in-criminal-proceedings-are-the-current-rules-fair

2. A near-miss
In Muhammad bin Kadar and another v PP [2011] 3 SLR 1205 (“Kadar”), two brothers were charged with murder. Midway through a lengthy trial, the prosecution disclosed to the defence statements from an eyewitness which consistently stated that only one intruder had been present at the material time.

The Court of Appeal therefore overturned the conviction of one of the brothers, Ismil bin Kadar.

Had the prosecution not disclosed this crucial evidence, an innocent man may have been sent to the gallows.

The Court of Appeal thus gave the following guidance in relation to the prosecution’s common law duty to disclose evidence prior to trial, even if it did not intend to rely on these (the “Kadar rules”):1

The prosecution must disclose any unused material that is likely to be admissible and that might reasonably be regarded as credible and relevant to the guilt or innocence of the accused; and
The prosecution must also disclose any unused material that is likely to be inadmissible, but would provide a real (not fanciful) chance of pursuing a line of inquiry that leads to material that is likely to be admissible and that might reasonably be regarded as credible and relevant to the guilt or innocence of the accused.