Yes, I am not talking about Syriza’s deal specifically, as you said Cosco has had a lot of presence before that, I am talking about the company’s dealings in general. I believe it started with Giorgos Papandreou (who is generally a big advocate for cooperation between the EU, Greece and China)? Idk I don’t remember but I remember reading from time to time sketchy shit they were doing while negotiating with both the state as well as workers, as well as bad labor conditions. They also apparently used Golden Dawn scabs to attack or threaten striking workers and journalists. Here is a few articles in Greek:

https://www.efsyn.gr/ellada/koinonia/174161_skoteino-prosopo-toy-kinezikoy-giganta

https://iskra.gr/επίθεση-χρυσαυγιτών-σε-δημοσιογράφο/

http://www.katiousa.gr/epikairotita/ti-gyrevei-alepou-sto-pazari-synantisi-voulefti-tis-cha-tin-presveira-tis-kinas/

The last one is about an MP of Golden Dawn having a meeting with the Chinese ambassador, which definitely had to do with Cosco.

I haven’t paid too much attention but there is a lot of things wrong with Cosco. Perhaps Belt and Road would be good but I don’t automatically trust it. But again I haven’t read too much about it.