Professional Game Match Officials Limited have revealed that they are to launch an investigation into referee Mick Russell, who failed to send off Sheffield Wednesday's on-loan midfielder Jeremy Helan earlier today.

Russell showed Helan two yellow cards in Wednesday's 0-0 draw with rivals Huddersfield Town but did not produce the expected red afterwards.

Town manager Simon Grayson admitted that he was "staggered" by the referee, and now PGMOL have announced their investigation into Russell.

A statement read: "The Professional Game Match Officials Limited are to conduct an investigation into an incident that took place in the Huddersfield Town v Sheffield Wednesday game in the npower Championship on Saturday.

"In the eighth minute of the match Mick Russell, the referee, stopped play when Jeremy Helan was adjudged to have simulated an offence inside the Huddersfield penalty area. However, it appears that instead of Helan (number 24) receiving a caution, one was given instead for Michail Antonio (number 7).

"In the 25th minute Helan was cautioned following a foul challenge. As the referee had not previously recorded his name he did not issue a red card for receiving a second caution in the same game."

The statement also revealed that Russell has admitted to making an error.