Uncertainty has surrounded the business for weeks.
The Enquirer understands that around 100 of the 122 staff were made redundant earlier this month.
But subcontractors have been unable to find out what is happening at the company which claims to have a £120m-a-year turnover.
Phone calls to HOC’s central London went unanswered.
One worried supplier said: “We have tried for days to speak to someone but had no joy.
“We will be putting a claim in for the money they owe us.”
HOC was set up in 2010 by Hugh O’Connor.
The firm’s latest major win was in March when it was appointed main contractor on a £20m residential development at Pages Walk in south London for O’Callaghan Developments.
Just days before HOC was appointed main contractor by Criterion Capital for its £25m redevelopment of Bedford House and Canterbury House in Croydon.
An update on the Datalog website shows Opus Restructuring LLP was appointed as administrator on Friday.