Police said the truck struck the pedestrian aged in his 50 to 60s as he attempted to cross Queens Street about 4.40pm on Wednesday.

The truck, carrying green P-plates, is parked on Queen Street while about a dozen police cars and emergency services remain at the scene.

Investigators have been told the truck was travelling north along Queen Street when it hit the man who died at the scene near Bourke Street.

Roads were closed between Lonsdale Street and Little Bourke Street westbound and also Little Bourke at Queen Street but had reopened by 11pm Wednesday.

Motorists are being urged to seek an alternative route.

Anyone with information, who witnessed the incident or has dash cam footage is urged to call Crime Stoppers on 1800 333 000.