WASHINGTON - (KRT) - Prices for cocaine and heroin have reached 20-year lows, according to a report released Tuesday.

The Washington Office on Latin America, which usually is critical of U.S. policies in Latin America, said the low prices called into question the effectiveness of the two-decade U.S. war on drugs. A White House official said the numbers were old and didn't reflect recent efforts in Colombia to curb drug cultivation.

The Washington Office on Latin America, citing the White House's Office of National Drug Control Policy, said the street price of 2 grams of cocaine averaged $106 in the first half of 2003, down 14 percent from the previous year's average and the lowest price in 20 years.

An official with the Office of National Drug Control Policy confirmed the figures, which haven't been publicly released.

The report comes as the Bush administration and Congress work with Colombian authorities to craft a successor to Plan Colombia, which will end late next year after pumping more than $3 billion into Colombia to fight drugs since 2000.

The Washington Office on Latin America accused the White House drug-policy office of not releasing price and purity numbers since 2000 because the data were "inconvenient."

"It strays too far from the message of imminent drug-war success, particularly around Plan Colombia," said John Walsh, a senior associate with the Latin America organization.

The organization said that not only had the price of cocaine on U.S. streets dropped to a fifth of its 1981 level, but heroin was much cheaper too. A gram of heroin, which cost $329 in 1981, sold for $60 in the first half of 2003, it said.

The drug policy adviser said Bush administration officials thought those numbers no longer reflected reality.

"We're always looking in the rearview mirror," said the official, who requested anonymity.

The official said the government of President Alvaro Uribe in Colombia, which took office in 2002, had made big gains in cutting back coca crops with fumigation campaigns and has put the drug industry "under duress." The drug-policy office figures on coca eradication in Colombia show a 33 percent decline in acreage under cultivation from 2001 to 2003.

"This does not preclude surprises," the official said. "This is an adaptable snake (but) we have a stranglehold on the snake."