"Officers investigating a reported death of a British citizen in Syria are today carrying out a search of a house in Manchester," Detective Chief Inspector Will Chatterton of the North West Counter-Terrorism Unit said in a statement.
"As part of this inquiry, officers are also providing support to the family and are speaking to them to understand how a man from the northwest came to be reportedly killed in Syria."
A neighbour recalled that Raoufi had been an ordinary football-loving teenager, but underwent a noticeable change around three years ago.
"When you spoke to Anil on the street he would not say hello like the others did," she said.
"He started wearing the robes as well. I was quite frightened of him a little bit. He was not the same."
European countries face a growing number of young people going to fight in Syria, where a civil war is raging involving President Bashar al-Assad's forces, rebels and Islamist fighters.
British officials say hundreds of Britons are currently believed to be fighting there.
A senior police officer warned last month that anyone returning to Britain from Syria risked being arrested.
On Wednesday, British police searched a home in the southeastern town of Crawley as part of an investigation into reports that a man named as 41-year-old Abdul Waheed Majid was responsible for a suicide attack in Syria.
He reportedly carried out a suicide truck bombing on February 6 as part of an attack by rebel fighters on the jail in the divided northern city of Aleppo. Rebel fighters are held in the prison.