A retired Baltimore police officer has described the shocking abuses he claims to have seen other cops commit on the job.

Michael A Wood, 35, alleges he saw detectives kick suspects in the face, urinate on their beds during home raids, and illegally search people with no justification on a daily basis.

The allegations came in a slew of tweets on Wednesday as the former Marine slammed America's 'corrupt' policing system.

And he promised followers this is just the start: 'I'll do some each day so that we have time for [questions], reflections, and improvement inbetween (sic). The light of transparency will clean us up.'