Police believe that a man wanted in connection with the death of Violet-Grace Youens has fled the country.
The four-year-old passed away in hospital last Saturday, just over 24 hours after being struck by a stolen Ford Fiesta in a hit and run incident on Prescot Road.
Her grandmother Angela French, 55, was also injured and remains in a serious but stable condition.
Detectives probing the incident have arrested 27-year-old from St Helens on suspicion of causing both death and serious injury by dangerous driving.
However police are looking to trace a second man, shown in CCTV images, who travelled overseas in the hours after the nan and granddaughter were hit.
Detective Chief Inspector Chris Sephton said: “We believe that a second male, aged 23, who we would like to speak to, is abroad.
“He left approximately three hours after the incident.
“We have been in contact with the authorities of the country where we believe he is. We are not releasing that information at the present time.
“But we are doing everything we can to try and identify where he is now and get him back over here.”
Another third man, aged 23 and from Prescot, was detained on suspicion of being carried on a stolen vehicle but released pending further enquiries.