Story highlights Investigators search man's home and office

Berlin attacker had Tunisian's phone number, officials say

(CNN) German federal police have detained a Tunisian man who had possible ties to Berlin Christmas market attacker Anis Amri, according to a statement from the federal prosecutor's office released Wednesday.

Federal police searched the 40-year-old man's home and office with a search warrant from the federal court December 26, the statement said.

The man's phone number was found on a mobile phone belonging to Amri, according to the prosecutor.

"Further investigation points to the assumption that he could have been involved in the attack. He was therefore detained," the statement said.

"Whether or not the current suspicion against the detainee will become more substantial will be subject to further investigation," it added, saying the probe will determine whether an arrest warrant should be issued for the man.

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