Newcastle have written to the Premier League to question recent refereeing decisions they feel have gone against them.
Eddie Howe's side, who are second-bottom of the Premier League, have been punished by debatable calls in their last three matches, all defeats, with the manager criticising the decisions afterwards.
In a 4-0 defeat at Leicester, Howe said he could not understand how referee Peter Bankes awarded a penalty to the hosts, their first goal of the game, after James Maddison appeared to make the most of contact by Jamaal Lascelles.
Against Liverpool, Jurgen Klopp's team scored an equaliser and their first goal when Isaac Hayden lay on the six-yard line with a head injury.