A D.C. government employee responsible for purchasing supplies for a division of the Department of Health is under investigation for allegedly channeling city orders through a private Internet business for which he received commissions, according to city officials.

Winston G. Nicholas, who created and ran a Web site business called Nich Online Information Brokers (NOLIB), and other Health Department employees allegedly used a city government-issued credit card to purchase department supplies from vendors linked from his Web site. The purchases in question were made in 2002 and totaled at least $33,600, according to Herbert R. Tillery, interim director of the Department of Health.

The D.C. Office of the Inspector General is investigating the allegations to determine whether Nicholas violated city law by using or encouraging others to use his Web site. Government employees are prohibited from using their public office for private financial gain. If found in violation of the law, Nicholas could be moved to another position or fired, said city officials, who also are investigating whether all the purchases were for the D.C. government.

Nicholas, 47, has worked for the city for 22 years and is in charge of ordering supplies for the Office of Primary Care, Prevention and Planning. He said he has operated his Web site for eight years but denied using it in connection with his city job.

At times, he said, the Web site has had as many as 300 links to vendors that offer computer equipment and software, office supplies, toys and clothing. Nicholas said he is paid referral fees from vendors when shoppers order merchandise through links from his Web site.

"I've never used it to order government materials," Nicholas said. "Why would I do something that stupid? . . . It would be a conflict for me to be using my personal stuff to gain from the government. I use [the Web site] for my own personal purposes."

Nicholas said it is not a lucrative business. In 2002, he said, he made $2,000, all of which was used to maintain the site. He said his commission checks do not identify the vendor or the customer who made the purchase.

"I personally don't know of any $33,000 being spent on my Web site," Nicholas said in an interview at his attorney's office. "I have no way of telling the source of where the orders came from."

He said he still operates the Web site, www.nolib.com, but plans to take it down.

Tillery said that city employees no longer have the same access to city-issued credit cards to order supplies. He also said that his staff has interviewed Health Department employees to determine whether they once used Nicholas's Web site to order government supplies and confirmed that two employees had done so.

One of those employees and a third employee said in interviews with a reporter that they used the site to order government supplies after Nicholas encouraged them to do so.

Over the past year, the inspector general has collected credit card receipts and interviewed current and former Health Department employees about the Web site, according to city employees assisting with the investigation.

"There's a problem," Tillery said. "I want to make sure we do a thorough inquiry."

Tillery also said he wants the inspector general to subpoena vendors to determine how much commission Nicholas may have earned. "It's the principle," he said. "Even if it wasn't but $50, you cannot use your government position for personal gain."

Nicholas, whose annual salary is $67,814, said that he started the Web site business in 1996 to tap into the new market created by Internet shoppers and that he solicited family and friends to use the site.

In the Health Department's primary care office, Nicholas was authorized to purchase office supplies ranging from paper goods to computers with a city credit card issued to his supervisor, Michael S.A. Richardson, then a senior deputy director in the department. At times, Nicholas said, he allowed other employees to use the credit card.

Mia Diggs, a former clerk-typist who worked with Nicholas and has filed a sexual harassment claim against him, said she told the inspector general's office that she ordered supplies through his Web site over nine months starting in March 2002. Although she did not work directly for Nicholas, she said he suggested that she use the Web site because it streamlined the purchase process. She said she paid for the orders with Richardson's city credit card.

She provided copies of invoices for $2,736 in supplies, including a bookcase, hanging files, oscillating heaters and Jolly Rancher candies. City records for 16 orders placed in 2002 with the credit card issued to Richardson matched the dates, vendors and charges on the invoices supplied by Diggs. But neither the invoices nor the credit card records list the name of Nicholas's Web site.

"I did a lot of different orders through the Web site," she said. "I didn't know he was getting paid for it."

Nicholas said he does not know if any of the commissions he received from sales on his Web site came from purchases made by Diggs and other Health Department employees. His attorney, Edward C. Bou, said that it is going to be hard to prove that his client did something wrong unless the investigators have documents.

In two instances, city officials are trying to determine why orders placed with Richardson's credit card listed Nicholas's home in Northwest Washington as the delivery site.

In May 2002, an $845 Dell computer monitor went to his home. In January 2002, an order from Staples listed his daughter's name and his home address. The $99 Staples order, which included No. 2 pencils, rubber bands and three school notebooks, was redirected to the office before it was shipped, he said.

Nicholas said that staffers in the Health Department had mistakenly used his home address when they ordered the monitor and that he had returned it to the office. In the second case, he said some of his co-workers must have put his daughter's name on the Staples order to get him in trouble.

Richardson asked Nicholas to take the Web site down in early 2003 and acknowledged in an interview that he reported allegations about the site to the city's inspector general. Richardson left the department in October 2003.

Diggs was moved to another job in the department after she filed a sexual harassment lawsuit against Nicholas last year. The lawsuit, Nicholas said, shows that some staff members have a vendetta against him. In a statement made to an official investigating the complaint, Nicholas said the allegations about sexual harassment started after he was promoted.

In an interview, he said co-workers also are falsely accusing him of misusing his Web site.

"I'm trying to get to the bottom of it," Nicholas said. "It's like someone taking a shot with a machine gun hoping one bullet will hit. That's the strategy I see being employed."

Staff researcher Bobbye Pratt contributed to this report.