Hundreds of construction workers could be turning up to worksites unqualified after a Sydney man was arrested for selling fake health and safety white cards, police have warned.

The man from Sydney’s northwest was arrested on Tuesday for allegedly selling at least 400 cards to unqualified workers.

Police say the 37-year-old Kellyville man completed online white card training falsely claiming to be someone else before providing the white cards to people for a fee.

He is set to face Parramatta Local Court in November charged with four counts of fraud.

Superintendent Arthur Katsogiannis said there could be hundreds more fraudulent cards in circulation.

He said the Identity Security Strike Team (ISST), made up of the NSW Police Force and Australian Federal Police (AFP), received information in July 2015 relating to the fraudulent supply of work health and safety “white cards” to unqualified workers and started investigations.

“The construction industry continues to be one of the state’s highest risk,” he told reporters in Sydney.

Police will be alleging the man, who purported to work for a Registered Training Organisation was making at least $100 profit off each card, he said.

The man allegedly took money off workers who didn’t speak English or who had just come to Australia, Supt Katsogiannis said.

SafeWork NSW is helping police with the investigation.

“Any business with concerns about fraudulent licences should contact SafeWork NSW on 13 10 50,” said SafeWork NSW executive director Peter Dunphy.