A Hong Kong intern doctor arrested on suspicion of unauthorised access to patient data has been released on bail after about 21 hours in custody and has reportedly been escorted back to her former workplace for evidence collection.

A source told the South China Morning Post that the 24-year-old woman, surnamed Lai, was released from Cheung Sha Wan Police Station at around 4.30pm on Saturday.

She was arrested at around 7pm on Friday on suspicion of accessing a computer with dishonest intent.

A force spokesman said the suspect was released on bail and was required to report to police again in early July.

Lai was reportedly taken back to Caritas Medical Centre, her former workplace, on Saturday at noon, with the suspect spotted in casual wear and wearing a face mask.

Police received a report from a doctor at the centre in Sham Shui Po on June 10. The Hospital Authority fired her on Friday for misconduct.