Tama-chan, a wild Japanese seal who sparked a media frenzy after he got lost in a polluted Yokohama river, had evaded capture by concerned ecologists.
Tama-chan was given a local residence permit
Scientists from the Marine Animal Lifeline attempted to capture the animal using nets spread across the Katabira river, in order to return him to the sea.
But Tama-chan had other ideas, and managed to slip away before the gap between the nets was closed.
The attempt was not without controversy though, as local fans of the 11month-old bearded seal protested at the attempted capture.
About 20 Tama-chan fans attending the 'rescue' argued that he should be left to live on the concrete riverbank he had adopted.
It is totally isolated from its fellow seals. It will become sick if it lives in the dirty river for long
Yuji Awano, Marine Animal Lifeline spokesman
Later they tried to disrupt a press conference organised by the would-be rescuers.
Yasuo Tanaka, head of the local Tama-chan fan club told the AFP news agency that he thought the seal should not be captured.
"Tama-chan is healthy and has adjusted to the environment here," he said.
But Yuji Awano, a spokesman for the Marine Animal Lifeline held a different view.
"It is totally isolated from its fellow seals. It will become sick if it lives in the dirty river for long," he said.
Since appearing on the Tama river in August 2002, Tama-chan has been adopted as a local mascot.
Toy manufacturers produced look-alike action figures and his movements around the Tokyo bay area rivers were followed closely by local media.
He was even made an honorary citizen of Yokohoma, which angered long-term foreign residents unable to get the same privilege under Japan's strict citizenship laws.