"The Colbert Report" has been temporarily suspended due to the host's mother, Lorna Colbert, 91, falling ill, sources close to the show say.

Since news broke early yesterday morning that new episodes of "The Colbert Report" had been abruptly put on hold due to "unforeseen circumstances," speculation as to the reason has ranged far and wide. Many fans suspected a family illness, while others speculated that the host had been fired or that he was engaging in some kind of bizarre PR stunt.

While "The Daily Show" has previously cancelled shows at the last minute -- once for the birth of Jon Stewart's second child and once after the death of a staffer -- this is the first time "The Colbert Report" has done so.

On Thursday, a person who has a business relationship with the network told The Huffington Post that the host's mother was seriously ill, and on Friday, The New York Post cited an additional source who confirmed the illness.

According to that source, the network has remained tight-lipped over the situation because the Colberts are "a very private family.”

Colbert was born the youngest of 11 children to his mother Lorna and father James Colbert. Tragedy struck the family in 1974, when James and two of Colbert's brothers, Peter and Paul, were killed in the crash of Eastern Air Lines Flight 212 in Charlotte, N.C. Colbert was 10 years old at the time.

Fans and supporters have been tweeting messages of love and support for Colbert and his family since early Thursday. The show will continue in reruns until the host is able to return.

Lorna Colbert appeared on a South Carolina television station talking about her famous son in 2008:

And here is quick clip of Colbert reminding his audience why Mother's Day is so important: