HARTFORD, Conn. (AP) _ An investigator says he now belives the nation's worst circus fire was set by a teen-age circus hand and not ignited by a discarded cigarette, as authorities have maintained for 46 years.

The circus hand, now 61, denied setting the fire that killed 168 people in the big top of the Ringling Bros. and Barnum & Bailey circus on July 6, 1944.

The fire came to be known in circus lore as ''The Day the Clowns Cried.'' Famous clowns, including sad-faced Emmett Kelly, and Karl Wallenda of the Great Wallendas high-wire act were among performers credited with heroic acts in trying to extinguish the blaze and rescue people.

Among the dead was a young girl known only as Little Miss 1565, the number given her at the morgue.

Hartford Fire Lt. Rick Davey, who spent the last nine years investigating the fire and now believes it was set, also solved the mystery of the girl's identity.

Based on Davey's evidence, the state medical examiner's office issued an amended death certificate Friday to include her name, Eleanor Cook, the 8- year-old daughter of Mildred Cook, who also lost a son in the fire.

John M. Bailey, chief prosecutor for Hartford County, met Monday with city and state fire officials and representatives of the medical examiner's office to discuss Davey's findings. He planned to announce Tuesday how he would proceed.

Davey concluded that on the day of the fire, it was so humid that even a cigarette tossed into dry hay would not ignite. Witnesses also said the fire started 8 feet up on the tent.

Davey re-examined the confession of Robert Dale Segee, a 14-year-old runaway and circus hand at the time of the fire. Segee told authorities in Columbus, Ohio, in 1950 that he had set the fire.

Segee later recanted and Connecticut officials apparently never questioned him. He served eight years on arson charges in Ohio in the 1950s and was arrested again on an arson charge in 1960.

Segee, now 61 and living in Ohio, declined to discuss the circus fire.

''I can't talk to anyone about that,'' he told The Hartford Courant. ''It happened too long ago. I don't want to. I've been tested enough and they ruined my life. I didn't set the fire.''

For years, people believed Little Miss 1565's family also perished in the fire. Like many who died, she was trampled by the panicked crowd and not severely burned.

Mildred Cook, who is now 85 years old and living in Easthampton, Mass., told the Courant she always believed her daughter was one of seven unidentified fire victims. She said she never tried to find out for sure because it wouldn't bring the child back.

Cook took Eleanor to the circus along with her two sons, aged 6 and 9. The younger boy also died in the fire.

Cook herself spent six months in the hospital, her burned body bandaged from head to toe except for a slit allowing her to see.

Eleanor is now buried in a Windsor, Conn., cemetery. Mildred Cook said she wants to bring her daughter's body home and bury her beside her brother.

''I'd like them to be together,'' Cook said. ''And maybe have a little service and a hymn.''

Davey discovered Eleanor's real identity after sifting though mounds of documents in the State Library. He found that Eleanor's aunt went to the morgue, but refused to - or couldn't - positively identify the body shown her.

Davey presented his findings to federal arson investigators two weeks ago at the FBI Academy in Quantico, Va. They agreed that a cigarette could not have started the fire, but refused to comment on Davey's arson theory, saying the case represents an ongoing investigation.