The Foyle MP was speaking in the British House of Commons on Monday.
“I think Simon Byrne absolutely made the right decision in resigning today given everything that has happened in recent weeks.
“But there is a much deeper and more significant problem than just one individual. It is something we have been warning about for years. It is the real crisis in recruitment and retention of Catholic officers and staff to the PSNI,” the SDLP leader told MPs.
Mr. Eastwood called the introduction of 50/50 recruitment to ensure more Catholics are enrolled at the PSNI.
Secretary of State Chris Heaton-Harris replied: “I am a great believer, I guess, in the kind of original aspects of policing, ‘Peelism’, where a police force should be reflecting the community that it polices.
"That is how it gains its confidence. I believe that actually recently, and I might be mistaken, but I believe I was briefed that recently there have been good levels of recruitment from Catholic communities into the PSNI.
“However, it is situations like the one we are talking about today that damage the prospects of that moving forward and it is our job, it is all of our jobs, to make sure that doesn't happen.”
The exchange took place as Mr. Heaton-Harris responded to an urgent question on the recent PSNI data breach tabled by DUP leader Jeffrey Donaldson.