Thomas Lane, 37, had been held on $750,000 (£590,000) bail but was freed from Hennepin County Jail on Wednesday, sheriff's office records showed.
He was one of three officers charged with aiding and abetting second-degree murder and aiding and abetting second-degree manslaughter in Mr Floyd's death on 25 May.
A fourth officer, Derek Chauvin, was videotaped pressing his knee to Mr Floyd's neck as he gasped "I can't breathe" and called for his mother before he died.
Chauvin was charged with second-degree murder and second-degree manslaughter.
All four officers have been fired from the Minneapolis police department.
Lane's lawyer Earl Gray has told media that his client tried to help Mr Floyd, including trying to resuscitate him in the ambulance.
Mr Gray also told the media that Lane was only on his fourth day on the job on patrol duty and that Chauvin was his training officer, whom he should obey.
"What was my client supposed to do but follow what his training officer said?" Mr Gray said in a court hearing, Forbes and other media reported.