China has detained five people as part of its probe into a firm that allegedly supplied out of date meat to fast food chains, including McDonald's and KFC.

State-owned Xinhua news agency said the five were held by the Shanghai police, but did not give any further details.

Chinese regulators suspended operations of Shanghai Husi Food earlier this week after reports in local media claimed it re-processed expired meat.

Shanghai Husi is the Chinese unit of US-based food supplier OSI Group.

John Sudworth reports.