A three-week investigation into working conditions in the factories of Apple in China by the US Fair Labour Association (FLA) has found that there is widespread flouting of employment rules at the Foxconn plants.

The FLA investigation has revealed excessive overtime and unpaid overtime compensation, several health and safety risks and unsafe working conditions among workers.

The investigation has found out that employees often worked over 60 hours a week and sometimes for seven days a week without the mandatory one day off. It happened though the Chinese labour law limited the weekly working hours to 49 hours a week.

The association has also found that Chinese workers at the Foxconn plants do not have a genuine trade union representation.

The FLA conducted the investigation after a request from the iPhone and iPad maker to look into the working conditions and safety standards at its supplier Foxconn following widespread allegations into the working conditions of the employees.

There was a string of suicides at the Foxconn factories in 2011 that was attributed to poor working conditions in the plants by rights groups and activists.

The FLA investigation has found that there are significant issues at the factories and said it has secured agreements from Apple to keep working hours within legal limits, protect pay, and improve staff representation.

Apple has agreed to comply with the recommendations of the association by July 2013.

"We share the FLA's goal of improving lives and raising the bar for manufacturing companies everywhere," said Apple in a statement.

The report followed the visit of Apple CEO Tim Cook to the Foxconn facility at the Zhengzhou Technology Park where 120,000 workers are employed.