"Why should we have an international inquiry?
We will object to it ... Definitely, we are not going to allow it," Economic Development Minister Basil Rajapakse, who is President Mahinda Rajapakse's brother, told AFP.
His comments came after British Prime Minister David Cameron said he would push for an international investigation through the UN human rights council unless the government acts by March to credibly address claims of abuses at the end of the war.
The Rajapakse regime is carrying out its own more limited investigation but has consistently denied any civilians were killed in the last stages of the war when government troops routed Tamil Tiger rebels in their last stronghold.
The UN and rights groups however have said as many as 40,000 civilians may have been killed in the onslaught.
"It is not new, it is not the first time they are saying it," Basil Rajapakse said of the pressure for an international inquiry.
Asked about the March deadline for the Sri Lankans to comple