Nexia BT partner Karl Cini was spotted coming out of the police depot after reportedly facing hours of interrogations.
The Malta Independent published footage of Mr Cini emerging from the depot accompanied by his lawyer Stephen Tonna Lowell late on Thursday.
Mr Cini was being interrogated in relation to Egrant Inc., sources told The Malta Independent.
The Nexia BT partner had been inside the depot from early afternoon and came out at around 6.30 pm.
Nexia BT was at the centre of several cases of alleged money laundering and corruption, involving also Pilatus Bank and top Maltese government officials.
Mr Cini had reportedly given Mossack Fonseca the name of Egrant’s ultimate beneficial owner over Skype.
A magisterial inquiry into Egrant Inc had subsequently found no evidence linking Prime Minister Joseph Muscat or his family to the Panama company.
Mr Cini was also a key player in the Panama Papers scandal, having handled the offshore set-ups of the Panama accounts of Tourism Minister Konrad Mizzi and chief of staff Keith Schembri.
Read: MEP calls on EBA to expand investigation into Nexia BT
Mr Cini is not the first person to be interrogated by the police since the magisterial inquiry into the Egrant allegations was concluded. Two weeks ago, former FIAU officer Jonathan Ferris was also questioned for several hours.
Watch: Ferris sticks by Egrant testimony after three hours of questioning