A public inquiry is being held after the owners appealed against the council's compulsory purchase order (CPO) for the former of North Wales Hospital, Denbigh.
The hearing was told that owners Freemont (Denbigh) Limited were drawing up new plans for the site.
The hospital closed in 1996.
Solicitor Ayub Bhailok, who is assisting Freemont, said: "There is no justification for the CPO. There is a commercially viable scheme possible and the confidence in the market can only improve as time progresses."
Freemont took over the property from Acebench Investments Ltd, of which he is a director and which paid £310,000 for the hospital in 2003.
The company's own planning consent expired in 2009 after hopes of progress were halted during the building slump the previous year, the hearing was told.
Mr Bhailok claimed that since 2009, the council and Prince's Regeneration Trust had been determined to repossess the site and press ahead with their own scheme without involving him.
In 2011, Denbighshire council served an urgent works notice on the British Virgin Islands-based company after becoming frustrated at the deterioration in the condition of the listed buildings.
It then carried out the work and last October a public inquiry was held into the council's claim for £900,000 to be refunded by Freemont for the work.
A Welsh government decision on that is expected within the next three weeks.
Plans for a large-scale mixed development have been submitted on behalf of the Prince's Regeneration Trust, working in conjunction with the council.
If the CPO is confirmed, it is proposed that the property should be handed over to the North Wales Buildings Preservation Trust.
The hearing continues.
Efforts by owners to redevelop a Victorian hospital were impeded by Denbighshire council officials, a hearing has been told.