The Solomon Islands prime minister, Sir Allan Kemakeza, says his officials have now received a report about the fisheries minister's voting choices at the International Whaling Commission's meeting in South Korea in June.
The minister, Paul Maenu'u, defied cabinet instructions and cast votes in contradiction to Sir Allan's statements.
The minister's action prompted Sir Allan to apologise to an Australian minister for the embarrassment Mr Maenu'u had caused.
The opposition accused the government of dishonesty but Sir Allan's administration has rejected this and the prime minister said he might sack the minister over the incident.
Solomon Islands radio says the report has now reached his officials and Sir Allan will make a decision on Mr Maenu'u soon.
Solomon Islands voted for Japan's bid to resume commercial whaling.
