An Australian government ship should be sent to disrupt Japanese whaling in a similar fashion to the Sea Shepherd, the environment group's local head Bob Brown says.

Talking to Fairfax Media, the former Greens leader said there would be a lot of ''sniggering'' in Tokyo about the federal government's decision not to send a customs vessel to the Southern Ocean this summer to monitor Japanese whaling activities, breaking an election promise.

Last summer’s whaling season was marked by several high seas collisions between Japanese and Sea Shepherd boats. Credit:Eliza Muirhead/Sea Shepherd Australia

On Sunday Environment Minister Greg Hunt said instead an aircraft would be used from January to March to monitor whaling and any clashes between Japanese vessels and those of the Sea Shepherd.

Dr Brown said three Sea Shepherd vessels – the Bob Barker, the Steve Irwin and the Sam Simon – were currently on-route to intercept Japanese whaling boats, which he said was expected to take place before the end of the year.