A bribery scandal involving reconstruction efforts in the earthquake-damaged Friuli region of Northern Italy has tarnished the government's image and seems likely to create political problems for the ruling Christian Democratic Party.

Sixteen months after the quake that took almost a thousand lives and left nearly 100,000 persons homeless, the region is being rocked again, this time by charges of corruption.

The arrest last week of a top official in the government's emergency reconstruction office in Udine has led to a judicial investigation of government contracts for the 20,000 prefabricated homes erected in the area.

The investigation has embarrassed Premier Giulio Andreotti's minority Christian Democratic government, which was proud of its efficiency and speed in meeting the emergency and enjoyed pointing to the contrast between the Friuli operaion and the corruption-riddled reconstruction program that followed a 1968 earthquake in Sicily.

After the first big earthquake in May 1976 and a second in September, Andreotti appointed a special commissioner for the area and gave him almost unlimited emergency powers and a $120 million budget.

The commissioner, Giuseppe Zamberletti, 43, an under secretary at the powerful Interior Ministry, presided over the emergency housing program with widely recognized enthusiasm and zeal.

Last week Zamberletti expressed "despair, shock and surprise" at the arrest of his personal secretary and long-time collborator, Giuseppe Balbo, accused a taking a $15,000 kickback, from the Precasa prefab construction company.

Balbo reportedly has admitted receiving the money and using it to pay the debts of a needy person in the damaged area. According to the Milan newspaper Corriere Della Sera, that person is Roberto Brollo, son of the Christian Democratic mayor of Artegna, a village in the disaster area. Brollo's brother is the son-in-law of the Christian Democratic mayor of Maiano, who was arrested on corruption charges earlier this month.

Zamberletti has urged Italians not to judge the government's entire Friuli program by "one weak link in a chain." But he and top Christian Democratic leaders are known to be concerned that traditional Italian cynicism toward politicians will surface.

Ironically, the Christian Democrats were so proud of putting a roof over every head in the earthquake area by the end of March that they scheduled this year's National Friendship Festival in the Friuli area, one of the party's traditional strongholds.

The festival is the party's answer to the Communists' traditional Festival of Unity to be held this year in Modena.

"But now," said one of the festival's organizers, "we're likely to find ourselves confronted by banner-waving extremists accusing us of being the same old corrupt party as in the past."