Police have visited the head office of BNP Paribas as part of an investigation into Bernard Madoff, a judicial source has told Reuters.

The bank has reportedly confirmed that police have asked for papers and has said it reacted with "complete transparence" to a request it considers "completely artificial".

The move is believed to be related to a lawsuit brought by a BNP Paribas client in connection with the bank's investment in Luxalpha, a fund managed by UBS in Luxembourg and invested with Mr Madoff.