The health of Nigeria's President Umaru Yar'Adua is again a source of speculation in the Nigerian media, with some reports suggesting he may have undergone surgery in Saudi Arabia. Nigerian officials say President Umaru Musa Yar'Adua received medical attention, but they say the president is in good health and went to Saudi Arabia for religious pilgrimage, not a medical procedure. Gilbert da Costa reports for VOA from Abuja.

When news broke last week that President Umaru Yar'Adua was receiving medical attention in Saudi Arabia, the Nigerian media latched on to it. The Nigerian leader's health has been a source of constant media speculation.

Doubts emerged about the president's health after he was flown to Germany for treatment after collapsing during a campaign tour in March last year, just weeks ahead of the presidential election. He has since returned to Germany a couple of times for medical checkups, the latest in April.

Some Nigerian newspapers said on Sunday that Mr. Yar'Adua, known to have a kidney problem, has been hospitalized in Saudi Arabia, where he may have undergone a renal transplant.

Nigerian authorities say the president is in good health and in Saudi Arabia for a religious pilgrimage, not for medical attention. The government said in a statement he was expected back in Nigeria soon after his pilgrimage.

A leading opposition party, the Action Congress, says Nigerians deserve to know the whole truth about the president's health. Party spokesman Lai Mohammed told VOA regular briefings are necessary to ease concerns about the president.

"His health is no longer a private issue because his health or illness has so much repercussion on the economy, on the social stability and on the security of the nation," he said. "So if a person like that, holding that office is indisposed the public, Nigerians, must know that he is indisposed. We believe that the information management is faulty. And they kept us in the dark."

Senior government officials deny Mr. Yar'Adua's planned official trip to Brazil had been put off due to the president's ill health.

Fifteen months into his presidency, Mr. Yar'Adua still faces a legal challenge to the legitimacy of the 2007 election. The Nigerian leader is also struggling to deal with an insurgency in the key Niger Delta where attacks on oil industry targets continue unabated.