Libya's failure to attend a Moslem conference in Morocco led to unconfirmed reports today that its leader, Col. Muammar Qaddafi, is grappling with acute unrest, including a mutiny by troops near the Egyptian frontier this month.

Libya promptly denied that a rebellion had occured or that the government has declared a state of emergency in Tobruk, scene of the reported uprising by an army brigade in which 400 persons were said to have been killed or wounded.

[a U.S. official said the State Department had received no information confirming that such an Army revolt had taken place at Tobruk.]

Qaddafi, increasingly at odds with Egypt's President Anwar Sadat because of the latter's signing of the Camp David peace agreement with Israel, in recent months has constructed extensive new military fortifications along the Egyptian frontier. Egypt, which attacked Libyan bases in this area in 1977, maintains a state of military alert along its Libyan border.

In describing the alleged troop mutiny, Arab diplomatic reports earlier today from Morocco, where Moslem states are meeting to discuss Jerusalem said that loyal Libyan troops brought the revolt under control with help of East German adviser. Libya has an estimated 1,000 East German and Soviet advisers to help with security and witht he assimilation of Libya's arsenal of Soviet-made military hardware.

Western sources in Tripoli, the Libyan capital, were quoted by news agencies as saying that unrest involving military personnel broke out in Tobruk two weeks ago but appeared under control. They said that life in Tripoli appeared normal.

[However, the Egyptian newspaper Al Akhbar said an Egyptian military source had confirmed that fighting was still raging between loyalists and rebels in the Tobruk area, according to news agencies. The Middle East New Agency said the fighting was still going on but the rebels have been besieged. The agency was quoted as saying 400 persons had been killed or injured.]

The rule of Col. Qaddafi, who has put Libya's oil wealth behind radical and terrorist causes, has aroused growing resentment in Libya, Western diplomats said. A Libyan defector told Paris-Match Magazine this week that Qaddafi has nearly bankrupted Libya and has started a campaign against Libya's small middle class to obtain a new source of funds for the government

Gunmen have assassinated a number of Libyans living in Europe this summer because they refused to return home. The killings followed apparent appeals for such actions by official media.

In light of Qaddafi's increasingly violent criticism of President Sadat, there has been persistent speculation about possible Egyptian encouragement of Libyan opposition groups. Reports of the alleged Tobruk mutiny said that some survivors have fled to Egypt and sought asylum there. At least one source said that some resistance is continuing within the Libyan forces.

The same Arab diplomatic sources said that the pilot of a Libyan Mig 23 aircraft which crashed in Italy last month was trying to escape from Libya. It allegedly was shot down by a missile fired from a Soviet naval vessel.