Bangladesh's cricket authorities on Sunday filed a police complaint against three Indian nationals for illegally betting during the country's first Test against West Indies, officials said.

The Test is being held behind closed doors, but police said the three had managed to find a way into Chittagong's Zahur Ahmed Chowdhury Stadium on Saturday.

"The BCB accused them of betting through digital means inside the stadium. They were formally arrested today," said Hasan Imam, a senior Chittagong police officer.

"We are also investigating how they were able to go to the stadium when spectators are banned."

Almost all gambling is illegal in Bangladesh but it is rampant during cricket matches, when underground punters exploit a brief delay between live play and official broadcasts to place bets.