Samu recently moved to the New South Wales Waratahs, after finishing the Top 14 season with Bordeaux.
“We are pleased with the First Nations and Pasifika XV’s preparation for their inaugural match against the Lions at Marvel Stadium on Tuesday,” the Rugby Australia spokesperson said.
“Pete Samu is a valued member of the Waratahs and has added greatly to the First Nations and Pasifika squad since entering camp.”
Meanwhile, Kefu told the Sydney Morning Herald he was bewildered by the Lions stance.
“I still can’t believe that they would do it, complain about it. I suppose it is what it is, but it’s extra motivation for our boys,” said Kefu, who played 60 times for Australia.
“We’re a team that’s just been put together, we’re facing a massive challenge as it is, so he [Samu] would have definitely strengthened us, there’s no doubt about that.
“They must have been worried we were going to win. I don’t know why they would do it.”
The Lions insist Samu has not been blocked, but is simply not eligible for the match.
“I think it’s more the rules and regulations of what was agreed before the tour,” assistant coach Johnny Sexton said on Friday.
To add to the confusion, Samu was allowed to play for the Australia and New Zealand Invitational XV last weekend, a match the Lions won 48-0.
Over the weekend the Lions will fly in the Scottish pair Ewan Ashman and Rory Sutherland to play against the First Nations and Pasifika XV in order to ensure none of the Test team have to play twice in five days.
Scotland winger Darcy Graham has also been added to the squad, as has Leinster prop Thomas Clarkson, England hooker Jamie George and Leinster back Jamie Osborne, with the Lions squad swelling from 38 players to 44.