Police have beefed up security around Mahendra Singh Dhoni after he received extortion letters from a man claiming to be an associate of the country's most wanted gangster.
Police said on Wednesday they had sent more than 45 commandos to Dhoni's house in his hometown of Ranchi, the capital of the eastern state of Jharkhand, one of India's poorest states.
The first letter, sent on Monday, threatened Dhoni's family with dire consequences if the player failed to pay 5 million rupees ($102,000), police said.
A second letter on Wednesday threatened to blow up the captain's family home if police were asked for help.
Dhoni arrived in Ranchi on Tuesday and met a local police official on Wednesday to discuss the threat.
"The letter has been sent by one Taslim who claims to be a close associate of Dawood Ibrahim," Satya Narayan Pradhan, a Jharkhand police spokesman, told Reuters.
Dawood Ibrahim is India's most wanted man for allegedly masterminding the country's most deadly bombings in 1993, which killed at least 250 people in Mumbai.
The underworld boss has eluded authorities for the past 15 years and is believed to be hiding in Pakistan. By the 1980s and 1990s, he was one of Mumbai's top gangland leaders, with a billion-dollar vice empire spanning gambling, drugs and prostitution.
Police say they have started an investigation into the letters.
Dhoni had already received extra security cover after Maoist rebels made death threats against him last year, police said.
But he was unhappy with the arrangements and applied for government permission for his security to carry more sophisticated weapons.