A Supreme Court judge in Victoria has upheld an injunction temporarily halting the sale of Tasmanian dairy business Van Diemen's Land (VDL) Company to an undisclosed foreign buyer.

Tas Foods, formerly Oncard International, has taken the New Zealand owners of VDL to court, alleging their contract to buy the company was breached.

The judge ordered the defendants to provide Tas Food's lawyers with details of its sale contract with the foreign buyer.

The injunction has been extended until next week, when the case will be back before the court.

TasFoods entered into a sales agreement to buy VDL from the New Zealand-based New Plymouth District Council (NPDC) in early November.

Weeks later, the NPDC announced it was pursuing a new bid from an unnamed foreign private company.

The identity of the buyer is subject to a full confidentiality agreement and will not be disclosed until the deal is finalised.

The new agreement is conditional upon Foreign Investment Review Board approval.

The council said the offer from the private company was "commercially superior" to the bid from TasFoods.

In a statement on the ASX, TasFoods said the price agreed in the deal struck with the foreign buyer was less than its bid, which was in excess of $280 million.