In a statement for the ASX, TAP managing director, Paul Underwood, said the information has the potential to confuse shareholders "as the latest estimate does not state what the estimated recoverable reserves are."

He cautioned shareholders on premature speculation as to the value of the Hovea discovery based on the preliminary estimates only. He said recoverable volumes are often subsequently determined to be only a fraction of the oil initially in place, and can often result in a discovery being uncommercial or unviable.

Underwood went on to say that while Tap believes this will not be the case at Hovea, the Tap offer factored this risk into its bid, and would continue exploration into the discovery.

He said he expected to have the bidder's statement to Arc shareholders on 27th March.