SEATTLE — Picasso's daughter isn't recommending buying fine art at http://costco.com.

A drawing listed at $145,999.99 was removed from Costco Wholesale Corp.'s Web site this week after one of Picasso's children, Maya Widmaier-Picasso, questioned the authenticity certificates of that drawing and two others the company already has sold.

Costco has begun probing the authenticity of "Picador in a Bullfight," along with two others it sold over the past two years, Jim Sinegal, chief executive of the nation's largest wholesale-club, said yesterday.

"We're still trying to ferret out where we're at on this thing," Sinegal said yesterday. He said the company had thoroughly researched the authenticity of "Picador in a Bullfight" and the other two before they were offered for sale.

"That doesn't mean we're infallible," he said, adding, "We would be terribly embarrassed if there was a flaw in our system."

The company called the customers who bought the other drawings from Costco.com when it learned that The New York Times was preparing a story questioning the authenticity of similar drawings. The Times published a report on the issue yesterday.

Sinegal said both customers have declared themselves satisfied with their purchases, but if it turns out the drawings are not authentic, they will be offered their money back.

Florida art dealer Jim Tutwiler has been selling art through Costco for the past decade. He described a crayon-on-paper Picasso drawing sold in January 2005 as a "doodle" on the blank side of a book jacket. The work was signed and dated Nov. 29, 1970.

That drawing and a Picasso sold in November 2004 on costco.com both came with a handwritten and signed declaration from Widmaier-Picasso.

But Widmaier-Picasso, 70, told the newspaper Tuesday that she questions the authenticity of "Picador in a Bullfight" and its authentication certificate, which also purports to have been drawn up and signed by her. She contends the document is a forgery, citing problems ranging from grammar to handwriting.

Sinegal said Costco officials checked the authentication certificates that accompanied their drawings and found only one of her five concerns to be an issue on the company's certificates, which were further verified by the International Society of Appraisers.