A database containing the personal information of more than one million school pupils in Beijing is being offered for sale online raising fears of a possible hacking incident.

The list posted on baixing.com late Sunday promises the names and telephone numbers of primary and secondary children as well as their parents for 0.1 yuan ($15 cent) each if a minimum purchase of 1,000 is made.

How the seller accessed the data remains unclear. He told Beijing Youth Daily he paid four million yuan to get the list with the help of contacts.

Beijing Times was told he collected the data from a communication platform widely used among the capital's primary and secondary schools to send messages to parents.

Samples were provided to both newspapers. The Beijing Times claims the information is 90 percent accurate.

One parent surnamed Wang filed a complaint after he was continuously called by a number of tutorial agencies. He said "they just keep calling me like every two or three days, asking if my child needs to attend tutorial classes."

The trader selling the list claimed 30 copies had already been sold, mostly to educational guidance agencies who promised not to resell the information or use it illegally.

One school principle denied the data was hacked, but did not rule out the possibility of an internal disclosure by faculty staff to a third party.

As of Monday the post had been deleted.