Belgian Abdelhamid Abaaoud has been singled out as a key figure in the plot that saw 129 people murdered in coordinated strikes in the French capital on Friday.
The official said the man was also thought to be behind a plot to kill Christians at a church near Paris in April.
Police arrested three men in time to stop the attack which was thought to be targeted at a church in Villejuif, south of Paris.
It's claimed Sid Ahmed Ghlam, an Algerian living in Paris, is also accused of killing a woman nearby and detectives claim to have found guns and a note with church details in his car.
Premier reported in April that a search of the suspects home uncovered three Kalashnikov assault rifles and computers showing he had been in contact with jihadis in Syria.
Abdelhamid Abaaoud
The French official has now said Abdelhamid Abaaoud, who planned the Paris attacks, was also the mastermind of the church plan.
He is from the suburb of Molenbeek in Brussels and is thought to be of Moroccan origin but currently living in Syria in so called Islamic State territory.
Islamic State's online magazine Dabiq featured an interview with him earlier this year in which he boasted about being able to travel through Europe undetected.
Meanwhile security at churches in France has been high since August when police revealed fears of a plot to shoot worshipers on the Feast of the Assumption.
A letter from the country's Interior Ministry to Christians, published in France's Catholic daily newspaper La Croix, urged caution at services.
"Every religious gathering, whatever its magnitude, is vulnerable today to acts of malevolence, which may extend to terrorism," it said.
"Observing simple rules may allow you, without excessive distrust, to ensure your security and that of your community, while preserving the calm (and) sharing openness to others, which is needed for maintaining your faith and religious practices."
Churchgoers were encouraged to report 'very nervous' people and those who showed 'an unusual interest in the event or the building'.
Parishioners were told not to leave bags on pews as they went up to receive Communion.