Media playback is unsupported on your device Media caption Chinese drug salesmen admit paying bribes. Martin Patience reports

Bribes are routinely paid by major foreign pharmaceutical firms operating in China, the BBC has learned.

Five drugs salesmen for foreign companies told the BBC their firms paid bribes in order to increase sales of their products.

None of them wanted to be identified, fearing they would lose their jobs.

The revelations come as Beijing widens its investigation into drugs-price fixing amid a bribery scandal engulfing drugs giant GlaxoSmithKline.

'Inflated prices'

One of the salesmen said his company paid about $1,000 (£647) to get its product back on the shelves at one hospital.

It may cost us more if we have not paid the bribe. It will be a lot of money and energy Salesman China drug costs: The human price

"I don't deny [giving money to doctors] happens in foreign companies," the sales representative said. "It is rare though and only very few people get it," he added.

But he described an incident where a product had been cleared from a hospital's shelves, which proved to be "an embarrassment" for him and his company.

"If we follow the normal procedure to recover it, it is very complicated. It will cost a lot of money and energy. We looked for a quick way."

He admitted that strictly speaking, the money paid out to ensure the product returned to shelves was probably a bribe and that his manager signed it off. He said it would have cost a lot more to achieve the same result through official routes.

"It may cost us more if we have not paid the bribe. It will be a lot of money and energy," he said.

Such revelations follow last month's allegations by the Chinese police that the British drugs giant GlaxoSmithKline had engaged in "mafia-style behaviour". GSK was accused of directing up to £320m through travel agencies to facilitate bribes to doctors and officials.

A detained Chinese executive from the firm told state television that bribes paid by his company had inflated prices of its products by a third.

GSK has said that it is co-operating with the Chinese investigation.

China's health care spending is expected to more than double by the end of this decade.

By investigating possible drugs price fixing the authorities are hoping to tackle the rising costs.