Tunisia's Interior Ministry says police have arrested Anis Amri's nephew and two others suspected of belonging to the same extremist network.
The ministry says in a statement that Amri — suspected of driving a truck into a Christmas market crowd in Berlin, killing 12 — had sent his 18-year-old nephew Fedi money to join him in Europe.
It is unclear whether the suspects helped Amri flee Berlin.
The nephew was arrested in Amri's hometown of Oueslatia while the others were arrested in Tunis. The arrests occurred Saturday.