Australian government insists its bilateral relations with Japan are not being strained by the whaling issue.

Japan has reportedly hit out at Acting Prime Minister Julia Gillard over her handling of last week's collision between the anti-whaling speedboat, the Ady Gil, and a whaling vessel in the Southern Ocean.

The bow of the Ady Gil, which belongs to the Sea Shepherd Conservation Society, was sheared off in a collision with the Japanese ship Shonan Maru 2 last Wednesday.

Japanese officials said Gillard's call for restraint on both sides would strain diplomatic efforts on the issue, The Australian reports.

Officials told acting ambassador to Japan Allan McKinnon on Friday that it was "not appropriate" because the Ady Gil was " conducting the unlawful rampage."

Acting Foreign Minister Simon Crean disagrees. "I don't think it is going to impact upon our relationship," he told the Australian Broadcasting Company, adding that Australia should continue to urge "restraint" over whaling.