Authorities said that 17 pounds of weapons-grade uranium disappeared and that a verdict in the trial of four men accused of trying to sell the radioactive material will be delayed until it is found, state media reported Friday.

The report was the first public word that uranium was missing.

The defendants said they did not know where the uranium was because it had been moved around so much between potential buyers, the China Daily newspaper reported.

The uranium was typesU-235 and U-238, both of which can be used to make nuclear weapons. Prolonged exposure to the radioactive material can cause cancer.

Defendant Zhang Sangang said he met a uranium mine owner in April 2005 and offered to be a middleman. The owner said he wanted $26,400 per kilogram, and that Zhang could keep the difference if he found someone willing to pay a higher price, the report said.

The three other defendants joined Zhang in his plan, and one of them met a businessman in the city of Guangzhou who said he knew someone willing to pay $210,000 for a kilogram of the uranium, the newspaper said, citing testimony in Guangzhou's Tianhe District Court.

But the businessman reported defendant Li Zi'an to police because he knew it was illegal to sell uranium.

The uranium mine owner was being tried separately.