HDB has reply but no much information about the existing TA. I remove the title and the HDB officer signature.
Subletting Tenancy
We refer to your e-mail dated 23 Feb 2013.
2 The subletting tenancy agreement is a private contract between the existing flat owner and the subtenants which HDB is not a party to. Hence, HDB does not intervene if there is a dispute between the flat owner and the subtenants. In general, the flat seller has to deliver vacant possession of the flat to the buyer at the point of resale completion. You may wish to seek your solicitor's advise on possible avenues of recourse if this is not complied with.
3 Thank you.
Yours sincerely,