The offices of Alok Verma and Rakesh Asthana at the CBI headquarters in Delhi were sealed.

Highlights A late night order sent the CBI's Alok Verma and Rakesh Asthana on leave

M Nageswar Rao has taken charge as interim chief of the agency

Official messengers informed Verma and Asthana about "compulsory leave"

It was a 1 am "coup" that set in motion cataclysmic changes in the Central Bureau of Investigation (CBI), the country's top investigating agency, caught in a one-of-a-kind battle between chief Alok Verma and his deputy Rakesh Asthana.

Around 12:45 am last night, the preps started with the police cordoning off the CBI building in Lodhi Road in south Delhi.

At 1 am, sources say, National Security Adviser Ajit Doval summoned officers in charge of appointments to the Prime Minister's Office and asked them to put out the order sending the CBI chief on leave.

An order by an appointments committee led by the Prime Minister was put out, sending CBI director Alok Verma and his deputy Rakesh Asthana on leave and handing charge to an interim chief, M Nageswar Rao.

Rakesh Asthana (right) alleged that it was his boss Alok Verma (left) who is guilty of bribe-taking.

An hour later, around 1.45 am, M Nageswar Rao was escorted by a police convoy to the building for his takeover.

Mr Rao's first task after his late-night promotion was to seal the offices of Alok Verma, again escorted by the police.

After settling down in his own room, Mr Rao then put out letters sending officers in Alok Verma's team on leave - AK Sharma and Manish Sinha.

Finally, Alok Verma and Rakesh Asthana were informed about their "compulsory leave" through official messengers.

This morning, both were reportedly stopped from entering their office and their drivers were withdrawn. The offices of Alok Verma and his team were reportedly searched.

Staff who came to work this morning were told to return in the afternoon. There would be no movement of officials or files at the offices of Alok Verma and Rakesh Asthana till afternoon, sources said.

As the controlling authority for the CBI, Chief Vigilance Commissioner KV Chowdary had submitted his recommendation on Tuesday to Prime Minister Narendra Modi - that Alok Verma, Rakesh Asthana and many other officers be sent on compulsory leave.

Mr Chowdary had been asked by the Prime Minister's Office on Monday to step in and give his report on the CBI battle, which escalated after Alok Verma's team filed a police case against Rakesh Asthana, accusing him of taking bribe from a businessman on the agency's radar. The CBI director also launched an investigation against Mr Asthana, who, in letters to the government, had alleged that it was his boss who had taken bribe.

Mr Asthana was sent on leave on Tuesday, as he took the CBI to court and requested that the case against him be cancelled. Hours later, his boss was also out.