SHANGHAI, July 28  -- McDonald's restaurants in China are suffering a shortage of supplies after it decided to reject products from OSI China and any of its joint ventures, the fast food chain's China unit told Xinhua on Monday.

The American fast food firm is trying to get products from other suppliers, said a spokesperson from the company's public relations department.

A full menu is not expected in restaurants until early August, while some outlets may need more time, the spokesperson said.

The decision was made on Friday after public concerns over shifting business from scandal-hit Shanghai Husi Food Co., Ltd, owned by U.S.-based OSI Group, to Henan Husi.

On July 20, a local TV station reported that Shanghai Husi had supplied products tainted with reprocessed expired meat to a string of fast food chains and restaurants across China.

KFC-parent Yum Brands Inc. has already announced a halt on purchases from OSI China and has been angered by the Shanghai unit's behavior.

In a press conference held by OSI Group on Monday, the company said it would investigate all of its units in China, and build an Asian quality control center in Shanghai.

It has stopped all operations at Shanghai Husi and will investigate current and former senior management. A new management team has been brought in to China.