The theft was brought to the company's attention internally, Mr Watson said.
"This is not the sort of activity that Svitzer can or will tolerate - and the company moved to deal with a totally unacceptable situation."
"There is absolutely no room for this sort of behaviour, and Svitzer dealt with it on the spot, in the most decisive way possible."
Mr Watson could not say whether charges would be laid against the men, who he said had been "sent packing".
He was also unable to say whether the wine belonged to Blenheim winemakers Astrolabe, whose company name proved a cruel irony when 4000 cases of its sauvignon blanc - worth about $800,000 - were on board the Rena when it crashed into the Astrolabe Reef.
Astrolabe general manager Jason Yank said some stock was in the rear section of the ship, which has since sunk, but he was unaware of any being stolen.
Inspector Karl Wright-St Clair said police were unaware of the incident.
The Maritime Union organiser at Port of Tauranga, Selwyn Russell, said that while he was not aware of all of the facts, the divers' actions were deplorable.
"It's not a good look."