The Anil Dhirubhai Ambani Group has alleged a conspiracy by possible business rivals to murder company chairman Anil Ambani after pebbles and gravel were found in the gear box of his helicopter and demanded a probe into the sabotage. The Mumbai police Crime Branch Friday evening decided to take over the investigations.

The Anil Dhirubhai Ambani Group wrote a strongly-worded letter to Chief Minister Ashok Chavan, alleging "a conspiracy to murder" its chairman Anil Ambani and demanding a thorough probe into the incident.

Announcing that the Mumbai Crime Branch was taking over the probe, Joint Police Commissioner Rakesh Maria told reporters late Friday evening: "We have asked the local police to transfer the case to us and we shall carry out further investigations into the matter."