Detect Bid Rigging in dataset, using Auto Model

So, in your opinion to find some bid rigging action in my dataset, what type of analysis do I have to do: Predict, Cluster or Outliners?

I have a dataset with attributes like: tender results (a flag awarded / not awarded), winner name company, winner bid amount, and other attributes; but I don't have an attribute that contains all the not winner offers of the participant, for each row surely.

So what would you do in my shoes?

Thank you so much for the future answer.

Best regards.
Ric