(CNN) Many of the YouTube videos Donald Trump appeared in prior to his presidential campaign, in which Trump often shared his thoughts on politics, are no longer available on the Trump Organization's channel.

In the four years leading up to Trump's run for President, the Trump Organization occasionally released videos titled "From The Desk of Donald Trump," in which Trump would share his thoughts on politics and current events. Most of those videos — 66 total, according to a Trump Organization playlist on YouTube -- have been made private, meaning only the user who uploaded the videos has access to them.

It's unclear when the videos were made private, but they were available throughout the 2016 presidential campaign.

Requests for comment to the Trump Organization and the White House were not returned.

Many of the videos that are now unavailable were a useful resource during Trump's campaign for determining the candidate's past political beliefs. The videos, like Trump's past television and radio appearances, provided a glimpse into Trump's unfiltered opinions on a variety subjects, including US foreign policy.

Some of the statements Trump made in the videos contradicted what he would go on to say on the campaign trail.

During the campaign, candidate Trump panned the 2011 US intervention in Libya, telling CNN's Jake Tapper in 2015 that the world would be better if leader Moammar Gadhafi were still in power. But in one 2011 video that has now been removed from YouTube, Trump urged the US to act in Libya to remove Gadhafi, saying "we should go in, we should stop this guy, which would be very easy and very quick."

CNN's KFile reported on these videos and many others during the campaign.

Other videos removed include Trump boasting about getting then-President Barack Obama to release his long-form birth certificate,Trump urging President Obama to protect Iranian protesters, Trump urging the US to withdraw from Afghanistan, and Trump questioning the President's birth certificate in 2012.

Clicking on old links to the videos returns the message "this video is unavailable." Some of the videos, captured by other YouTube users, are still available by searching the titles.

A small number of the videos were not removed, including ones where Trump talked about his induction into the WWE hall of fame, discussed Mike Tyson's Broadway show, commented on Occupy Wall Street, and bashed comedian Jon Stewart.