Former Kolkata police commissioner Prasun Mukherjee was on Tuesday questioned for the first time by the Central Bureau of Investigation in connection with the mysterious death of computer graphics teacher Rizwanur Rahman.

Mukherjee, who was removed from his post on October 17 along with four other police officers, had allegedly asked Rizwanur to part with his wife Priyanka, daughter of industrialist Ashok Todi, official sources said.

He was questioned by DIG CBI Satish Golcha and Superintendent of Police CBI Zaki Mohammed.

The two-member team met Mukherjee at his south Kolkata office at 10 am and talked to him for nearly one hour.

"We have interrogated Prasun Mukherjee, but in the interest of the investigation, we cannot say anything more right now," said Golcha.

When contacted, Mukherjee, who is now the additional director general, Telecom, declined to comment.

"I am at a meeting and I am not in a position to say anything," he said.

Earlier, four other police officers, who had allegedly threatened Rizwanur before his death on September 21, were questioned by the investigating agency.

They were Deputy Commissioners Gyanwant Singh and Ajay Kumar, Assistant Commissioner Sukanti Chakraborty and Sub-Inspector Krishendu Ghosh.