Two students were paid to identify a teacher to the man who beheaded him last Friday in an attack that shocked France, prosecutors have alleged.
Samuel Paty was targeted close to his school near Paris for showing cartoons of the Prophet Muhammad in class.
His killer, 18-year-old Abdullakh Anzorov, was shot dead by police shortly after the attack.
On Wednesday, prosecutors said Anzorov had paid two teenage students around €300 (£270; $355) to identify Mr Paty.
The killer told the students he wanted to "film the teacher [and] make him apologise for the cartoon of the Prophet [Muhammad]", anti-terrorism prosecutor Jean-François Ricard said at a press conference.
He said Anzorov had told them he wanted "to humiliate him, to hit him".
The students, aged 14 and 15, are alleged to have described Mr Paty, 47, to Anzorov and stayed with him for more than two hours outside the school until the teacher appeared, Mr Ricard said.
The pair, who cannot be named for legal reasons, are two of seven people the French authorities are seeking to prosecute over the brutal attack.
Online hate campaign
The prosecutor also said there was a "direct causal link" between the killing and an online hate campaign that was orchestrated against Mr Paty.
The campaign was allegedly launched by the father of one of his pupils. The man, 48, who has been named in French media only as Brahim C, is accused of issuing a "fatwa" against the teacher.
On Wednesday, Mr Ricard confirmed reports that Brahim C, who is also facing prosecution, had exchanged a number of text messages with Mr Paty's killer prior to the attack.
He also posted videos denouncing Mr Paty after he showed the cartoons in two lessons about free speech earlier this month
But Mr Ricard said the father's anger and statements in the videos were based on "inaccurate facts" because his daughter had not been in the relevant lessons.
Macron to attend national memorial
The prosecutor's revelations come ahead of a national memorial service in Paris for Mr Paty.
President Emmanuel Macron will attend the event at the Sorbonne University on Wednesday evening, along with the teacher's family and some 400 guests.
He is expected to posthumously give Mr Paty France's highest award, the Legion d'Honneur,
Earlier, the president held a call with Russian President Vladimir Putin and urged co-operation in fighting terrorism. Mr Putin described the attack as a "barbarous murder".
Mr Paty's killer, Anzorov, was born in Moscow and his family is from Russia's Muslim-majority Chechnya region in the North Caucasus. He had lived in France since 2008.
Mr Macron said he wanted to see a "strengthening of Franco-Russian co-operation in the fight against terrorism and illegal immigration", the French presidency said.
Russia has played down any association with the attacker. "This person had lived in France for the past 12 years," a spokesman for the Russian embassy in Paris told the Tass news agency on Saturday.
Mosque closed amid mass raids
Police have raided some 40 homes following the attack, and the government also ordered a mosque to close for six months.
The Pantin mosque, just north of Paris, was closed after it emerged it had shared videos on Facebook calling for action against Mr Paty.
In one clip, posted just days before the attack, it also shared his school's address.
The mosque later expressed "regret" over the videos, which it has deleted, and condemned the teacher's killing.
Meanwhile, mosques in the south-western cities of Bordeaux and Beziers were put under police protection after they reported threats.
"Such actions are unacceptable on the soil of the Republic," Interior Minister Gérald Darmanin said in a tweet on Wednesday.
On Tuesday, President Macron said the Sheikh Yassin Collective - an Islamist group named after the founder of the Palestinian militant group Hamas - would be outlawed for being "directly involved" in the killing.
He said the ban was a way of helping France's Muslim community from the influence of radicalism.
Why was Samuel Paty targeted?
Mr Ricard said Mr Paty had been the target of threats since he showed the cartoons of the Prophet Muhammad during a class on 6 October.
The history and geography teacher advised Muslim students to leave the room if they thought they might be offended.
Depictions of the Prophet Muhammad can cause serious offence to Muslims because Islamic tradition explicitly forbids images of Muhammad and Allah (God).
The issue is particularly sensitive in France because of the decision by satirical magazine Charlie Hebdo to publish cartoons of the Prophet Muhammad.
A trial is currently under way over the killing of 12 people by Islamist extremists at the magazine's offices in 2015 following their publication.
France's Muslim community, which is Europe's largest, comprises about 10% of the population.
Some French Muslims say they are frequent targets of racism and discrimination because of their faith - an issue that has long caused tension in the country.