Toronto police say they have arrested four people in connection with a “sophisticated and complex” mortgage fraud investigation dating back to 2013.

The investigation, dubbed Project Bridle Path, was launched in the spring of 2013 and involved several high-end properties in the city.

The police service’s financial crimes unit says the value of the fraud is estimated to be $17 million.

“Mortgages were to be secured on properties, however they were never registered and were misrepresented to the lenders,” Toronto police said in a news release issued Tuesday.

“Individuals and companies who were introduced as owners of the properties were not in fact the real owners.”

Police also allege that multiple false title insurance certificates and property insurance certificates were produced to lenders before money was released as a way to make the transactions look legitimate.

The lengthy police investigation has now resulted in four suspects being charged.

Police say Grant Erlick, a 45-year-old Toronto man, and 48-year-old Masumeh Shaer-Valaie, of Richmond Hill, have been charged with fraud over $5,000, conspiracy to commit an indictable offence, accessory after the fact to an indictable offence, and money laundering.

Arash Missaghi, a 48-year-old Richmond Hill man, was charged with fraud over $5,000, conspiracy to commit an indictable offence, accessory after the fact to an indictable offence, and uttering forged documents.

Police say 53-year-old Bob Bahram Aziz Beiki, of Toronto, has been charged with one count of forgery in connection with the case.

They are scheduled to appear in court on Tuesday at Old City Hall.