Alok Verma vs Rakesh Asthana: What we know about the warring bosses of CBI

India's premier investigating agency, the Central Bureau of Investigation (CBI) is witnessing an unprecedented crisis since the last few weeks.

The ongoing struggle between the two top bosses - Alok Verma and Rakesh Asthana -  of the CBI escalated on Monday as the investigating agency conducted a raid on the 10th floor of its own headquarters in New Delhi.

The CBI on Monday also arrested its DSP Devender Kumar in connection with bribery allegations against its special Director Rakesh Asthana. 

The arrest comes a day after the CBI registered an FIR against Asthana, Kumar and two others. 

Rakesh Asthana, on his part, has drawn up a list of cases against Director Alok Verma and other top CBI officials. He has apparently listed a dozen charges, double the number that the CBI has him docked for. According to latest reports, he has also approached Delhi High Court to get CBI's FIR against him quashed.

As crisis in the CBI continues, here's the background of the two top bosses who are at the centre of the infighting:

Alok Verma

Alok Kumar Verma was appointed as the CBI chief in January 2017 after being shortlisted from a list of 45 candidates. The committee that appointed him included Prime Minister Narendra Modi;  Mallikarjun Kharge, Congress leader in Lok Sabha; and JS Khehar, the then Chief Justice of India.

He took over as the 27th Director of the CBI on February 1, 2017.

Verma is a 1979 batch Indian Police Service officer and has been in services for close to 38 years. In all these years, he has served at 24 posts. He was the Delhi Police Commissioner before being appointed as CBI chief.

The IPS officer has also served as the Director General for Tihar prisons, police chief of Mizoram among others.

As director general of Tihar prisons, Verma had to take heat from Home Minister Rajnath Singh after the airing of the controversial BBC Documentary 'India's Daughter', which included an eye-raising interview from December 16 Delhi gangrape accused Mukesh.

Before this he was in news in December 2016, when he recommended the promotions of 26,000 police officers, of which many had not been promoted in over 20 years.

Rakesh Asthana

A 1984-cadre IPS officer, Rakesh Asthana was appointed as the special director of the CBI in October 2017.

The appointment of the Gujarat cadre officer had not gone down well with many. His appointment was even challenged in the court by senior lawyer Prashant Bhushan.

He was a part of the Special Investigation Team (SIT) that looked into the 2002 Godhra train burning case. He also investigated the fodder scam between 1994 to 2001 in which former Bihar chief minister, Lalu Prasad Yadav was convicted.

According to Prashant Bhushan, he is not fit for the post as his name figures in diary of Sterling Biotech, which is being investigated by CBI itself.