Van Leuwen, played by Paul Maxwell, is a character in the film Aliens.
Van Leuwen sits on the executive board on the gateway station and interrogates Ellen Ripley. He cannot understand why the Nostromo was self-destructed and she was the only survivor.
She explains the events of Alien, but he does not seem to believe her. She grows more and more agitated and he decides to revoke her pilot license until she has several months of psychiatric evaluation.
He also reassures her that LV-426 doesn't have any alien lifeforms, because they've colonized it with Hadley's Hope.