MINNEAPOLIS (AP) _ The author of a book about fraud and deception within the Vatican's bank has been charged with bilking more than $110,000 from the widow of the defense lawyer in a celebrated murder case.

FBI agents on Tuesday arrested Luigi M. DiFonzo, 41, and his wife, Diane DiFonzo, 38, at their home in Kennebunk, Maine. DiFonzo wrote ''St. Peter's Banker,'' about a Vatican banker who was convicted and imprisoned for fraud, misappropriation of bank funds and perjury in 1980.

DiFonzo and his wife each were charged with five counts of interstate transportation of fraudulently acquired money and one count of wire fraud. DiFonzo also was charged with three counts of mail fraud and Mrs. DiFonzo with one count of mail fraud.

They were indicted Nov. 22 by a federal grand jury in St. Paul. The indictment, unsealed Tuesday, charges that the couple swindled Elizabeth Anderson of Granite Falls out of more than $110,000 - virtually all of the estate of her late husband, Swen.

DiFonzo was being held in lieu of $60,000 bail in a jail in Portland, Maine. Mrs. DiFonzo was released on $60,000 bail.

According to the FBI, DiFonzo met the Andersons during the 1984 trial of Steven Jenkins, who was sentenced to life in prison for the ambush shooting of two bankers at a farm his father had once rented. Swen Anderson, Mrs. Anderson's husband, defended Jenkins at the trial.

Anderson died of a heart attack in February 1986. In the next three months, according to the indictment, DiFonzo persauded Mrs. Anderson to make him her financial adviser.

The couple is scheduled for an extradition hearing in Portland on Friday.