Multiple investigations prompted by Uber's admission that it concealed a hack could join together for one big mega-probe into the incident.
An EU working group which has responsibility for data protection will decide next week whether to co-ordinate different investigations taking place in the UK, Italy, Austria, Poland and the Netherlands.
UK authorities have already launched an investigation into the hack, which Uber CEO Dara Khosrowshahi said on Tuesday night had affected around 50m accounts.
The Information Commissioner's Office (ICO) confirmed on Wednesday that UK citizens had been affected and that it was carrying out its own investigation into the incident, along with GCHQ's National Cyber Security Centre (NCSC).
ICO deputy commissioner James Dipple-Johnstone said that the authority should have been notified by Uber immediately, and added: "Deliberately concealing breaches from regulators and citizens could attract higher fines for companies."