CAIRO—The children of Moammar Gadhafi were increasingly engaged in recent months in covering up scandals fit for a "Libyan soap opera," including negative publicity from extravagant displays of wealth, such as a million-dollar private concert by pop diva Beyoncé, according to a new batch of secret diplomatic cables released Wednesday.

The assessments by U.S. diplomats were published by the secre-spilling website WikiLeaks as Gadhafi vowed to fight to the "last drop of blood" to put down an uprising against his 42-year rule of the North African nation. At least 300 protesters are believed to have been killed by pro-government forces in the past week of clashes.

Growing anger over crass behaviour by Gadhafi's offspring, such as son Hannibal's 2008 arrest for beating servants in a hotel in Switzerland, may have helped spark the current uprising. "The family has been in a tailspin recently," a cable assessed a year ago.