Housing Benefit Reclaiming from Agent who is NOT agent now and will NOT be able to reclaim from land

Housing Benefit Overpayment

I was previously managing a property for a Landlord.
There was an Overpayment and Housing Benefit want to Reclaim this money from me.

This is a recoverable Overpayment as the tenant advised someone at the office who did not advise the accounts department. The money was paid to the landlord – who has since disappeared [and I believe he may have gone bankrupt].

I advised the council that we no longer manage this property and gave them the Owners details.
They advised me that "Regulation 101 of the Housing Benefit regulations 2006 allows recovery of an overpayment to be recovered from whom housing benefit has been paid. As you were the recipient of the payments I am unable to revise my decision to hold you responsible to repay the above overpayment"

As I only accepted the monies on behalf of the landlord - and as I can no longer get hold of him - can they still reclaim from me or can I tell them to contact the landlord direct?