Felicity Williams is a former president of the MSF union in Wales

BBC Wales understands that the TUC is looking into the claims against Felicity Williams.

The TUC would say only that there could be no comment while the issue is the subject of internal procedures.

Mrs Williams, general secretary of the Wales TUC for three-and-a-half years, was unavailable for comment.

The Western Mail has reported that she has been on "gardening leave" from her post for about eight weeks after a majority of staff members at Transport House in Cardiff signed a collective grievance complaint against her.

In Wales, half a million workers are members of trade unions, and I will be working hard to ensure that a fair deal for them and their families at work is top of our agenda Felicity Williams on taking up her job in 2004

The newspaper also claimed that a related hearing took place this week.

Mrs Williams' appointment at the head of the body representing some 500,000 members of affiliated unions in Wales was announced in April 2004.

At the time she took the job, the TUC said about 40% of the working population in Wales belonged to a union, which was the highest proportion in the UK.

When she was appointed, TUC general secretary Brendan Barber hailed it as a "real dent in the glass ceiling for women in the trade union movement in Wales".

'Real honour'

Mrs Williams said at the time she got the job: "It is a real honour and a big responsibility to take up this post.

"The challenges that we have in Wales, to give men and women a better deal at work, to improve our public services and to create a successful economy are challenges that trade unions want to play a full part in delivering," she said

According to her TUC biography, Mrs Williams was educated at Aberdare Girls' Grammar School before qualifying as a biomedical scientist.

She received a fellowship of the Institute of Biomedical Scientists at Bristol University in 1988 and was deputy head of microbiology for the Welsh Blood service for 10 years.

She was president of the MSF union in Wales and became assistant general secretary to the Wales TUC in April 2000.

Her interests were said to include "training and development, fairness at work, equality issues and the NHS".