A Sanford vessel has spent 25 days getting to the Falklands to pick up the crew from another of the fleet, the San Aspiring.
The vessel had been fishing for toothfish and doing scientific research off South Georgia since February.
The crew hadn't been able to get home due to Covid-19 restrictions and Sanford is now trying to find out more about the arrests.
In the Falklands a charge of violent disorder can carry a jail term of up to five years.
Royal Falklands Islands police inspector Barry Thacker told Morning Report there was a fight at Dino's Bar on 29 June.
"When we attended there were a number of people that were assaulted. It turns out that there were five people who were seriously assaulted receiving hospital treatment."
He said the three New Zealand sailors were arrested and were in police custody and would appear before magistrates tomorrow charged with violent disorder.
He said the cause of the fighting was still being investigated.
"Certainly, there would appear to be unprovoked attacks at this moment... There were three acting together that resulted in the serious injuries."
A Sanford spokesperson, Fiona MacMillan, said because the matter is before the courts, she's unable to comment on the charges, except to say Sanford will support the legal process and its crew.
She said the company's efforts to try and understand the events have been hampered by the different time zones.
MacMillan said the planned crew retrieval operation will continue, albeit slightly delayed, while the company waits for more clarity from the court process.