Regulators in the UK, US and Europe have opened investigations into eBay following the massive customer data breach.

In the UK information commissioner Christopher Graham has said that the watchdog is liaising with European data authorities to pursue possible legal action against eBay over its data breach.

Graham told BBC Radio 5 Live that the Information Commissioner's Office (ICO) is investigating the data theft that compromised up to 233 million eBay accounts.

"We're certainly looking at the situation," Graham said. "We have to work with colleagues in Luxembourg where eBay is based for European purposes. We were in touch with the Luxembourg data protection authority yesterday."

Usernames, encrypted passwords, email addresses, phone numbers, physical addresses and dates of birth were all stolen when one of eBay's databases was compromised by hackers.

The online auction site has claimed that there is no evidence that any financial data was stolen, however security experts have warned that the data lost could be sufficient for criminals to impersonate an individual when dealing with financial organisations.

The New York attorney general has already called for eBay to provide free credit monitoring for all customers affected, while three US states are currently conducting a joint probe into eBay's response to the cyberattack.

Florida, Illinois and Connecticut are investigating the security practices of eBay and the circumstances that led to the breach.

A spokesperson for eBay confirmed that the e-commerce site had been in contact with various government agencies.

"We have relationships with and proactively contacted a number of state, federal, and international regulators and law enforcement agencies," the spokesperson said. "We are fully cooperating with them on all aspects of this incident."