Ruud Lubbers (search), who stepped down Sunday amid allegations of sexual impropriety during four years as head of the U.N. refugee agency, has a long career in public service in the Netherlands and elsewhere.

Lubbers, a 65-year-old former Dutch prime minister, began a five-year term as the U.N. High Commissioner for Refugees (search) in 2001 following the retirement of Sadako Ogata (search). Under his tenure, the number of refugees worldwide declined to 17 million from 22 million.

Ron Redmond, chief spokesman for the Geneva-based agency, said Lubbers did it for free, returning his paycheck to the agency and paying his own travel and other expenses.

"He's one of the hardest-working people I have ever seen," Redmond told The Associated Press. "And what a lot of people don't know is that he has done it all for free. He has refused to take a salary," he said.

"Each year over the past four years he has given UNHCR about $300,000," Redmond added.

Lubbers resigned Sunday over sexual harassment allegations, but he maintained his innocence and blamed the media for his downfall.

Lubbers, who insisted the allegations were "made up" and "slander," told Annan he would be available to UNHCR until a successor is in place. His five-year term was scheduled to end on Dec. 31.

"All the reports have turned out to be hot air," he said in a phone interview with Dutch television program Netwerk.

He said he was resigning because "the pressure from the ongoing press messages is continuing, the people that bring them out are continuing, and it's becoming too much."

The child of a wealthy Roman Catholic family, Lubbers studied economics and entered politics after working in his family firm, Lubbers Hollandia Engineering Works in the Netherlands.

He served as Dutch economics minister in the 1970s and was a member of parliament before becoming prime minister in 1982, a post he held for 12 years, making him the long-serving Dutch premier since World War II.

Lubbers headed the World Wide Fund for Nature, known as the World Wildlife Fund in North America, and taught a course on globalization at Harvard University before taking over the refugee post.

In choosing Lubbers, U.N. Secretary-General Kofi Annan said his wealth of experience would serve him well in a job that relies heavily on lobbying governments to provide financial support to the agency.

Lubbers made a point of pushing the European Union to increase its contributions to refugee work.

The UNHCR, one of the largest U.N. agencies, has a staff of about 5,000 in 120 countries and an annual budget of about $1 billion.

"I really am looking forward to serve a specific cause of people who really are in trouble and to put my creativity there," said Lubbers in accepting the appointment.