MANAGUA, NICARAGUA, DEC. 16 -- James J. Denby, an American farmer whose light plane was shot down by Sandinista forces 10 days ago, today told his brother he hoped to be freed soon.

In his first appearance in public since he was captured, Denby was brought to the public relations office of the Sandinista secret police to see his brother William, a lawyer from Carlinville, Ill., who arrived Monday. Accompanying William Denby were a Nicaraguan, an American lawyer and a U.S. consular official.

On his way out after conferring for about 40 minutes, James Denby was asked how he had been treated. He answered, "Not too bad." Asked if he were going to be charged with a crime, he replied, "I have no idea." He was then whisked away.

Denby, 57, was flying to his ranch in northern Costa Rica when Sandinista Navy troops hit the fuel tank of his Cessna 172 plane with rifle fire, forcing him down. Since then, Sandinista authorities have accused Denby, an avowed contra supporter, of offenses ranging from flying a spy mission for the rebels to involvement in drug trafficking.

Denby "feels he is innocent and that in time he'll be allowed to go home," his brother told reporters.