Lawyers for the widow of the Pulse nightclub gunman said they have only just been told that the attacker's father was an FBI informant for 11 years.

Omar Mateen drove around Orlando the night before the nightclub massacre, visiting several places, the mayor said.

German federal investigators are looking into a Duesseldorf bank account held by the father of the gunman who attacked an Orlando nightclub, and are in contact with their American counterparts, a police spokeswoman said.