Officers arrested a 29-year-old man and a 26-year-old woman, both from Portsmouth, on suspicion of child neglect after a two-year-old girl fell from five-storey block Mulberry House, Bedford Street, in Somers Town on May 28.
The pair were also arrested for possession of a Class B drug.
They were subsequently released on police bail.
The toddler was initially described as being in a ‘life-threatening’ condition after falling from the fourth storey before her situation improved - with the last police update revealing she was in a ‘serious but stable’ condition at Southampton General Hospital.
Nearly a month on from the horrific episode, police are still continuing investigations – with the authority yet to decide whether to charge the couple.
A police spokesman said: ‘The two that were arrested remain under investigation, enquiries are ongoing. There’s no further update on the girl.’
Forensic officers were seen outside the block with officers inside the apartment taking photos the day after the toddler’s fall. The road had been cordoned off on the day of the incident.