With Malaysians stuck at home due to a coronavirus outbreak, food delivery services are increasingly popular -- but one customer has sparked an outcry by sending a helicopter across the country to collect a rice dish.

Police are investigating an alleged breach of virus rules after the aircraft landed in Ipoh city to pick up 36 portions of the rice dish and returned to Kuala Lumpur, 180 kilometres (110 miles) away.

Authorities have imposed a lockdown to battle a widespread Covid-19 outbreak, with people largely staying at home and travel between states banned except in exceptional circumstances.

Social media lit up with anger after images circulated online of the helicopter landing in a field at the weekend to pick up the takeaway from a well-known Ipoh eatery.

"What kind of nonsense is this?" one user posted on Twitter.

"There are people who can't travel back home to attend... funerals or to see their loved ones for one last time, because it's not a valid enough reason to get them a travel permit."

The dish, which usually contains fish, meat, vegetables and curry sauce, is popularly known as "nasi ganja" due to its supposedly addictive nature -- although it does not contain any drugs.

Police say the red helicopter had been granted permission to fly outside the capital but only for maintenance, not to collect food.

They have taken statements from several people, including the owners of the restaurant and the helicopter, and prosecutors will decide whether to take further action.

The identity of the customer is not clear, but the helicopter owner has defended the unusual delivery.

"All papers were in order... it was a quick pick-up," Mohamed Raffe Chekku told local media outlet Free Malaysia Today.