It probably is one of the most embarrassing moments for Colombian President Juan Manuel Santos when he was caught on camera with a wet spot growing on his beige trousers. The incident happened on Saturday while he was talking to political supporters in the coastal city of Barranquilla.

However, like a true trooper, the president ignored the damp spot that appears to be linked to a health problem and continued his speech, even as the video cameras captured the embarrassing moment and the images were posted in social media and had become viral.

According to the New York Post, Mr Santos - who studied at Harvard and London School of Economics and elected in 2010 - announced in October 2012 that he has a cancer diagnoses and plans to have the tumour surgically removed.

In a statement quoted by the daily, the president explained, "I have carried out all the routine exams recommended by the doctors, and there has been an abnormal growth of the prostate specific antigen."

He added, "With God's help, this will turn out to be only one of those challenges we all have to face in life."

Other celebrities have suffered similar experiences in the past.

One of them is American singer Nicki Minaj who allegedly pooped on her pants while onstage in 2011 and the late Michael Jackson whom Dr Conrad Murray revealed recently was incontinent and always wore dark pants while performing to mask his urinary problem.