This thread probably has the answers, and mentions Brisbane trying a dubious move against the Bulldogs a few years back, with Beasley having a shot after the siren:
https://www.bigfooty.com/forum/threads/standing-on-the-mark-double-team.851555/
This is from
2019 Laws of Australian Football:
19. DISPOSAL AFTER MARK OR FREE KICK
19.1 STANDING THE MARK AND THE PROTECTED AREA
19.1.1 Standing The Mark
When a Player is awarded a Mark or Free Kick,
one Player from the opposing
Team may:
(a) stand on The Mark;
(b) move along a lateral line without advancing beyond The Mark; or
(c) otherwise be directed by a field Umpire.
For the avoidance of doubt, all other Players from the opposing Team must
be positioned behind The Mark or otherwise outside the Protected Area
defined in Law 19.1.2.
This is the incident from the Brisbane vs. Footscray game (it's not easy to see with all the people on the ground!):