Aware has received around 80 workplace sexual harassment complaints over the past three years, with 30 lodged this year alone. Aware executive director Corinna Lim said: "The numbers might seem small, but we know this is just the tip of the iceberg."

In a survey it did in 2008, more than half of 500 respondents said they had experienced workplace sexual harassment.

"Aware is not an official channel to receive such complaints, yet we get the same number of complaints on sexual harassment as we do on domestic violence," she said. "This is despite the fact that a lot of women don't even realise this is something they can report even though they felt very uncomfortable."

At least eight women who claimed they were sexually harassed at work over the past two years told The Sunday Times that in the absence of clear company codes and procedures to prevent harassment, investigate complaints and protect victims, complainants are often given short shrift.

Those who fall victim to physical harassment can file complaints with the police about outrage of modesty, but should cases go to court, the charges are difficult to prove beyond reasonable doubt.

Taking civil action is not an option for all as complainants may have to hire a lawyer and the process can prove costly.

For about a year, Ms Margaret Phua, an administrative executive at an electrical firm, worked from a client's office at an educational institution. Around six months into her stint, the man in charge of the project for the client began goading her to wear tight and revealing clothes and would tell sexual jokes. He would refuse to discuss work with her if she wore trousers.

She eventually spoke to her own company as well as her client's boss. "All I wanted was a personal apology and for the harassment to stop," she said.

The man's boss then told her he had been admonished, and her own company asked her to move on. But within days, she was shocked to be handed a retrenchment letter - she was the only employee asked to go.

The police could not help much since verbal harassment is not an arrestable offence. She then went to the subordinate courts to lodge a complaint, but she soon gave up. "The process seemed lengthy and complicated, and there was a chance I would need a lawyer, which I could not afford," she said.