Based on reading an article in Temasek Review on 15th May 2011, I was under the impression that Esmaco is a company based in Australia and probably originating from there.
I managed to find out the following about Esmaco. Esmaco was originally owned by HDB Corporation Pte Ltd which then sold off its interest in Esmaco to Premas International Ltd. Premas International Ltd was a subsidiary of CapitaLand Ltd. CapitaLand had in 2005 sold Premas to United Group Limited (an Australian company).
So, today... UGL Premas is the holding company and Esmaco is its subsidiary. It is likely that many of the staff and management in UGL Premas and Esmaco would have been the same chaps that were around prior to the divestment by CapitaLand. Mr Ho Thian Poh may well have been holding on to his position in Premas even before the acquisition by the Australian company and quite possibly he may have been the General MAnager of the Jurong Town Council from before the 2005 acquisition of Premas by UGL.
I'm not making any insinuations here or alleging any wrongdoing. Just trying to give a more accurate picture of the status of Esmaco.
There is still the unanswered question as to how the Managing Director of Premas could also be the General Manager of Jurong Town Council and avoid any possible conflict of interest.