Never come across that requirement before. But if there is some valid reason you have to, you could do it, and only remit into that account the amount of money you need to remit into
Singapore. If there are some government fees that can only be paid by local bank transfer, wire that money to Singapore, make the payment, and keep the rest outside.
I'd push back on the supposed requirement and get an explanation for why it's required. Might be good to speak with multiple accountants/service providers.