BOSTON (AP) _ A developer has been sentenced to six years in prison for extorting money from the Church of Scientology in exchange for bogus information about a $1.5 million check forgery.

U.S. District Judge John J. McNaught also imposed the maximum $10,000 fine on George T. Kattar and ordered him to pay back $33,333 to the church.

''I don't know why I ever got involved,'' the 68-year-old real estate developer told the court Wednesday as family members wept. ''I can never repay my family for the embarrassment I caused them, and I am truly sorry.''

A jury found Kattar guilty in December of extortion but acquitted him of three wire fraud counts and one count of accepting stolen money. He could have been sentenced to up to 20 years.

The case began when the church offered a $100,000 reward for information about a failed attempt in 1982 to pass a bad check on a bank account of church founder, L. Ron Hubbard, who died last year.

The government charged that Kattar and a co-defendant, who was acquitted on all charges, decided to falsely blame the forgery on lawyer Michael J. Flynn, who had filed suits against the church on behalf of former members.

Prosecutors alleged the two kept a $33,333 initial payment from the church for the information, then tried to extort the remaining $66,666 of the reward through threats.

''You're finished ... your days are numbered,'' Kattar told former church official Geoffrey Shervell, according to a tape played at the trial. Defense attorney Michael Avery said Kattar's comments were simply hyperbole by a peaceful man trying to act like a mobster.

Assistant U.S. Attorney Gary Crossen, who had sought a 12-year sentence, urged McNaught to consider Kattar's reputed mob ties, including ''long- standing relationships'' with reputed former Boston mob boss Gennaro Angiulo. Avery denied the allegations.