THE AFL has confirmed a time-keeping error cost Richmond 11 seconds as the Tigers lost a cliffhanger to St Kilda at Telstra Dome on Saturday night.

Football operations manager Adrian Anderson said time-keepers failed to stop the clock late in the fourth quarter after a signal from umpire Stuart Wenn.

Kelvin Moore hit the post in the dying minutes of the game, with the Tigers trailing at the time by just four points.

Anderson said the error occurred when the clock should have been stopped when Wenn called time-on while recalling a kick-out in the last quarter.

Richmond has said it will complain to the league.