Two people suspected of links to an illicit gold syndicate were arrested in a late night operation b.
The Congolese club have told supporters they will be taking 60% off ticket prices in an effort to ensure a full house - and, more importantly, a fevered and intimidating atmosphere - for Sunday's visit by Pirates.
The game is in Lubumbashi at the new stadium that Mazembe have built in the copper-rich Katanga province, kicking off at 3.30pm.
Mazembe have also laid out their game plan as they seek to overcome a 3-1 deficit from the first leg at the Orlando Stadium last month.
Mazembe need to win 2-0 to go through on the away goal-rule, and coach Lamine Ndiaye says there will be an aggressive approach to try and wipe out the deficit as quickly as possible.
The coach says Mazembe go into the game buoyed by their win on Sunday over V Club from Kinshasa in what is the Congolese equivalent of Pirates against Kaizer Chiefs.
Mazembe won the early season league match 2-1 and the coach says it was "done in fine style".
"This victory allows the players to prepare for Pirates in a confident mood, which is essential," said the Senegal-born Ndiaye.
Elimination by Pirates would be a major disaster for Mazembe, who have been to the group phase of the Champions League for all but one of the past five competitions.
They were winners in 2009 and 2010 and semifinalists last year and are the only African side to have played in the Club World Cup final where they lost to Inter Milan.
Ambitious chairman Moise Katumbi, who is also the province's governor, has sunk millions of the state's money into making the club a force on the African continent but if they lose to Pirates they will suffer the ignominy of failing to get to the last eight.