Millwall's firm handed out a frightening leaflet to their most hated rivals following the death of one of their own.
Millwall and West Ham have one of the most infamous rivalries in English football history, with their feud more to do with the differences between supporters than anything which happened on the pitch.
Their bitter rivalry was depicted in the hooligan film 'Green Street' and continues to exist currently, even with the two sides not in the same division.
The rivalry across the Thames dates back to both sets of supporters working for different dockyard workforces and there have been tragic incidents over the years.
One of the most notable came in 1976 when Millwall fan Ian Pratt died during fights between the two firms New Cross station.
He ended up falling under a train and dying. But the response from Milwall's supporters was a equally as terrifying. As recounted by The Telegraph, Millwall fans handed out chilling leaflets at the Cold Blow Lane end of The Den containing a picture of Pratt and the words, "A West Ham fan must die next week to avenge him".
Millwall and West ham have been involved in a number of violent clashes. Image: Getty A decade on and 19-year-old West Ham Terry Burns was stabbed to death by a group of Millwall supporters on the stairs at Embankment Station.
Even past the millennium, the chaos did not stop. The 2009 League Cup meeting at Upton Park between the two was greatly overshadowed by violence.
A Millwall fan was stabbed outside when clashes ensured before the game and there were several delays as supporters invaded the pitch.
54 West Ham supporters were hit with lifetime bans as well as the club being hit with a £115,000 fine from the FA following the 3-1 win.
The last competitive meeting between the clubs was in 2012 when goals from Carlton Cole and Winston Reid gave West Ham a 2-1 win in the Championship.
West Ham were promoted to the Premier League and have been in the top flight ever since.
However, there is the possibility that both sides are in the same division next season. West Ham currently occupy the final relegation spot, while Millwall are third in the Championship after 34 games played.