Associated Press in Portland – Workers at nine of Nike's contract factories in Indonesia have witnessed verbal and physical abuse by supervisors against their colleagues and seen female employees being coerced into sex, according to a new report.

Employees complained of being forced to do overtime, seeing assembly-line workers fondled by managers and having access to medical care restricted, the findings from the watchdog group Global Alliance reveal. Nike, the sports shoe and clothing giant, paid for the report and acknowledged the findings were disturbing. The company said it welcomed the chance to improve conditions at the 25 Indonesian factories from which it buys products.

"Of course, many of the results are disturbing, but that's exactly what we wanted to find out," said Maria Eitel, Nike's vice-president and senior adviser for corporate responsibility. "While the messages are tough, we welcome them."

Global Exchange, a San Francisco-based human rights group, praised Nike for releasing the findings. "I find the conclusions surprising," said Jason Mark, a spokesman for the group. "I think it demonstrates a welcomed candour, but the question is what Nike will do with this information?"

Researchers from Global Alliance conducted hour-long interviews with 4,004 employees – six per cent of the workforce at the nine factories chosen. Subjects were picked at random, and the interviews were done without supervision from factory officials, said Rick Little, chairman of Global Alliance.

Global Alliance, formed in 1999, is a consortium of groups and companies – including the World Bank, Nike and The Gap, a major US clothing retail chain – committed to improving the professional and personal lives of factory workers, especially women, across Asia.

The alliance's first report, issued last year and focusing on Thai and Vietnamese workers, was criticised by labour groups for not concentrating enough on violations and alleged abuses.

Of the workers surveyed in the latest report, 56 per cent said they had seen supervisors verbally abusing colleagues. And 15.7 per cent reported observing improper sexual touching. Some 13.7 per cent said they saw physical abuse.

Workers reported seeing others punished for being late by making them clean toilets or run around the factory grounds. Others alleged the deaths of two workers were related to the denial of medication.