Indonesian export ban leaves Singapore short of granite, numerous construction projects delayed

Question: Is this the real reason behind Khaw Boon Wan scaling back HDB BTO projects?

The Star Online, 2 Feb 2014
A shortage of granite due to an Indonesian export ban has left several construction projects in Singapore in a rocky state.
Contractors said that there had been delays for various projects since the middle of this month.
The Indonesian government ban­ned a wide range of minerals from being exported globally on Jan 12. It stopped shipping granite aggregate to Singapore around the same time.
It is understood that the regulations issued by the Indonesian government say that exports of raw or unprocessed granite out of Indonesia are not allowed. Full story