MEXICO CITY (AP) — The son of a former presidential candidate missing for a week asked authorities Friday to stay out of what he called the “negotiation” for his father.

The statement to local media by the son of missing politician Diego Fernandez de Cevallos appears to confirm that his family believes he was kidnapped.

“We earnestly ask that they (authorities) stay out of this process in order to help the negotiation,” said the message signed by Diego Fernandez de Cevallos Gutierrez.

A photo of a shirtless, blindfolded man resembling the gray-bearded politician appeared on social networking sites late Thursday. An associated message reportedly asked family members to get authorities to stay out of the case.

The family’s statement Friday did not confirm that talks have begun, whether they have been contacted by kidnappers or what if any demands may have been made.

It is common for Mexican families to try to negotiate directly with kidnappers. But Fernandez de Cevallos’ long-standing position in President Felipe Calderon’s National Action Party makes their request more unusual.

Fernandez de Cevallos, 69, was reported missing March 15 after his abandoned vehicle was found near his ranch with traces of blood found on a pair of scissors.

The photo posted on Twitter shows a grim-faced, bearded man with a sheet of plastic in the background. The beard and shape of the face look like those of Fernandez de Cevallos, but the Federal Attorney General’s office has not confirmed the photo’s authenticity.

Medical experts interviewed on Milenio television said the man appeared to be alive.

Fernandez de Cevallos was the 1994 presidential candidate of the National Action Party, and while he finished second, his campaign helped lead to the party’s victory in the 2000 election, ending 71 years of single-party domination in Mexico.

Calderon has called him “a key politician in the Mexican transition to democracy” and he ordered federal authorities to help Queretaro state investigators in the search.

Fernandez de Cevallos has been an elder statesman for the party, a power broker who split his time between the Senate and as an attorney representing some of Mexico’s richest businesses.

So far, federal officials say they have no indication of his whereabouts.

“It’s a mystery now. Of course, for me, it’s very important to preserve the confidence on the privacy of this investigation,” Calderon said during a CNN interview this week in Washington. “We will find Diego and, of course, we are working with all the resources we have to find him.”

Calderon told CNN he did not think Fernandez de Cevallos was taken by drug gangs trying to send the president a message.

“No, the criminals used to send me a very clear message in another way. I think it’s a very sensitive case,” he said.

Then, gazing at a photo of a younger, healthy Fernandez de Cevallos, Calderon added: “It’s very tough for me, of course, because Diego is a very good friend of mine. A very good friend.”