Berlin police made the arrest early on Wednesday after searching the home and business premises of a 40-year-old Tunisian man in the southern Berlin district of Tempelhof.

Investigators were reportedly led to the alleged accomplice after finding his contact details in the phone belonging to the main suspect, Anis Amri.

Truck hijack

The arrest on Wednesday came nine days after the attack on a Christmas market in Berlin. Twelve people were killed and 48 wounded after a truck was purposely driven into a crowd on Breitscheidplatz. Of the 12 dead, six were German, while the Czech Republic, Italy, and Israel have also confirmed that at least one of their citizens had been killed.

The Polish truck driver of the vehicle Amri hijackedand rammed into the Breitscheidplatz Christmas market was also found dead at the scene after apparently trying to fight off the terrorist. The Islamic State claimed responsibility for the attack.

German authorities under pressure

Following a massive manhunt and a number of raids across Germany, 24-year-old Amri was killed last Friday in the Sesto San Giovanni suburb of Milan, Italy, after drawing a gun on police officers who asked for his identification. Since his death, more details have emerged about Amri's journey from Germany to Italy. Last Wednesday night, Amri allegedly took a long-distance bus from the Dutch city of Nijmegen to Lyon, France, where he was later caught on surveillance camera.

According to research by German broadcaster WDR, Amri was much better connected to the western German Ruhr region than previously thought. Since the end of 2015, he regularly commuted between Berlin and the Ruhr region where he is believed to have visited a dozen mosques. The 24-year-old Tunisian is also thought to have had particularly good contacts in Dortmund and to have possessed a key to a mosque where he stayed overnight.

Selfie ahead of attack

A report by German public broadcasters on Wednesday also said that Amri requested prayers from a fellow regligous believer and took a selfie before steering the hijacked truck into a Christmas market.

"My brother, everything is all right, God willing, I am in the vehicle now, pray for me my brother, pray for me," Amri wrote.

He then sent a selfie from the cab of the truck, which public broadcasters NDR and WDR said was fitted with a special breaking device that automatically stopped the lorry on impact.

Police initially apprehended the wrong suspect, a 23-year-old Pakistani, prompting huge criticism of the German police force. Authorities have also come under increasingly intense fire after it emerged that Amri was well-known to security services for his involvement with radical jihadis and was even under surveillance for six months.

ksb/kms (Reuters, AFP, AP, dpa)