Interpol has placed the head of anti-whaling group Sea Shepherd, Paul Watson, on its international wanted list.
The request to place him on the list was issued by Japan.
Interpol has issued a so-called blue notice, asking national police forces to pass on information about Mr Watson's whereabouts and activities.
But it has not issued a notice requesting his arrest.
Mr Watson says the notice does not make any sense.
"It's a blue notice which means it's not an arrest warrant, it's just so they can keep tabs on me. But they needn't have wasted their time, they could have just followed our website," he said.
"One thing that it does mean to me is that we're certainly getting to them. We cut their kill quotas in half and they're really desperate that we not go back down there this year.
"But I can tell them we'll certainly be back down in the Southern Ocean harassing them again in December."
Fewer than 5 per cent of Japanese admit to even eating whale meat.
