McDonald's outlets across China have yanked their flagship burgers from the menu, the company said Monday, as the American owner of a key supplier embroiled in an expired meat scandal offered consumers a personal apology.

Authorities in Shanghai last week shut a plant owned by privately-held OSI Group after a television report alleging it mixed out-of-date meat with fresh product. Police later detained five officials from the OSI subsidiary which operated it, Shanghai Husi Food Co.

McDonald's, one of the factory's many customers in China, has stopped using food from all OSI plants in the country "after listening to voices from all parties", it said in a statement.

"Some restaurants in China have therefore experienced shortages of some products," it added, but gave no details.

It did not say whether the chain had identified any food using expired meat.

McDonald's has more than 2,000 restaurants in China, according to its website.

Some outlets in Shanghai and Beijing pulled Big Macs, Chicken McNuggets and other items off the menu.

An operator from the McDonald's national delivery hotline said Monday that beef and chicken items were unavailable in the Shanghai area, though fish and pork could be ordered.

"We have stopped selling all products related to Husi for food safety. Products affected mainly used beef and chicken," he said.

At a McDonald's in central Beijing, counter staff told customers that the branch only had the Filet-O-Fish sandwich.

At every cash register, there were signs in both Chinese and English reading: "We regret to let you know that currently we will only be able to provide a limited menu at our restaurant."

- 'Completely unacceptable' -

The OSI Shanghai factory's customers in China included McDonald's, KFC, Pizza Hut, coffee chain Starbucks, Burger King, 7-Eleven convenience stores and Papa John's Pizza, according to the companies.

The owner of OSI Group -- based in Aurora, Illinois -- apologised in person to Chinese consumers at a news conference in Shanghai on Monday.

"What happened at Husi Shanghai was completely unacceptable and I hope that you will accept my personal and most sincere apology -- I am very, very sorry," chairman and chief executive officer Sheldon Lavin told a room packed full of mainly Chinese journalists.

"We accept that there must be some consequences and we take responsibility for the actions of those individuals working for our company."

The company announced several executive appointments to help oversee compliance.

"Our investigation has found issues that are absolutely inconsistent with our internal requirements for the highest standards, process and policies," David McDonald, OSI's president and chief operating officer, told the news conference.

State media said last week that authorities had confirmed allegations originally aired by Shanghai station Dragon TV that the factory used expired meat and mis-labelled products.

The "bad meat" scandal, as it has been called by Chinese media, has spread to Japan and Hong Kong.

McDonald's said Friday that its more than 3,000 restaurants in Japan had stopped selling products made with chicken from China, regardless of supplier.

Japanese convenience store giant Family Mart stopped selling chicken sourced from the Shanghai plant.

In Hong Kong -- a special administrative region of China -- McDonald's suspended sales of chicken nuggets and several other items including chicken burgers, salads and lemon tea after admitting it imported food from the problem factory.