A BAN on boating, fishing and swimming in the Murray River has been extended to Robinvale by the NSW State Emergency Service.

The river was declared an emergency area on October 18 when all boats were banned for a stretch downstream of Tocumwal Bridge.

The ban was extended to Barham Bridge last weekend and to Robinvale on Wednesday afternoon.

NSW SES incident controller Shane Hargrave said the ban applied to people on both sides of the NSW-Victorian border.

"Due to river rises from the current flooding situation, emergency services want to ensure the safety of the community as the floodwaters move downstream," he said.

"As part of the declaration no boats can enter the emergency area and people cannot enter the area for any recreational purpose such as fishing or swimming.

"NSW SES is urging people in the community to reconsider ... entering the river system while it is in flood. Not only does this endanger yourself, it places our emergency services in danger to rescue you if you need help."

NSW Maritime staff and NSW Police will patrol the river with support from Victoria Police, after members of the water police squad arrived in Swan Hill on Wednesday.

Emergency services and council personnel will be allowed to use the river for flood response activities.