JAMES CHIWASHA VILLAGE, Zambia (AP) _ Officials on Friday sharply lowered their estimate of the number killed when a barge sank on a river crossing from Zaire to Zambia, but said the exact figure may never be known.

Local officials also said the barge, the Maria, apparently was dangerously overloaded.

Authorities initially said the Maria was carrying 470 people when it sank Sunday, that 80 people swam to safety and 44 bodies were recovered. They said 346 people were missing and feared dead in the flood-swollen, crocodile- infested Luapula River.

But officials said Friday the known death toll was 51, and that about 190 passengers swam to safety. They estimated the total number of passengers at about 250.

Rescue workers searching for bodies near James Chiwasha Village on the river, overlooking the wreckage in northern Zambia, said the actual toll may never be known. They said bodies were still being washed ashore as far as 20 miles away, and crocodiles may have eaten other victims.

The Maria was making a routine crossing of the muddy Luapula River when it struck a rock or sandbar in early-morning darkness.

Local officials said the diesel-powered barge was licensed in Zaire to carry 150 passengers.

Besides carrying extra passengers, the barge was packed with 900 crates of Zairean beer that passengers intended to smuggle past customs officers, according to coxswain Chisanga Mwila. Mwila, a Zambian, was being held by police pending an investigation into the cause of the accident.

Police earlier maintained Mwila was dozing when the Maria sank, but refused Friday to say if he faced charges of negligence. Mwila said he had just handed the helm over to a crewmate when there was a crash and water rushed in.

Residents of James Chiwasha Village said the Maria often smuggled beer into Zambia and returned with cornmeal, goats, chickens and dried fish - all scarce commodities in Zaire.

Zambian Secretary of State Alex Shapi inspected the wreckage Friday and told The Associated Press, ''There is no doubt about the real cause of this tragedy. It is smuggling.''

He said smugglers used barges such as the Maria to travel at night and evade customs inspectors who, by law, charge heavy duties on most imports in both countries. Shapi called on the two governments to abolish import tariffs for goods trafficked on the river to prevent further disasters.

''People were shouting, 'We are going to die,' '' Mwila said. ''It was all I could do to swim to the Zairean bank of the river.''

Mwila said he hid in reeds for fear of being lynched by distraught survivors or relatives of missing passengers. Most of the other 24 crewmen, mainly Zaireans, have not been seen since the accident and may have fled, he said.