The motive behind the murder of Madhya Pradesh RTI activist Shehla Masood continues to be shrouded in mystery even after investigators arrested three persons including a woman interior designer, in this connection.

While the CBI arrested interior designer Zahida Pervez and Shakib Ali "Danger" from here, the UP police has apprehended one person from Kanpur.

Whether the murder was the result of a relationship that Shehla is said to have with Zahida's husband or was it professional rivalry between the two over getting contracts from the Madhya Pradesh Tourism Development Corporation (MPTDC) for their alleged proximity with BJP MLA and then MPTDC Chairman, Dhruv Narayan Singh, are some questions that the central agency needs to probe.

Sources said it was Shehla, who had introduced Zahida to MPTDC, but when she got closer with the then Chairman and started getting contracts, the RTI activist created hurdles by filing number of RTI applications to block the projects.

Efforts to contact Dhruv Narayan on the issue proved futile as he remained unavailable.

Though CBI has already quizzed Narayan in this regard, whether it will call him again for further investigations in the light of new developments in the case, is not yet clear.

CBI spokesperson, Dharini Mishra said that "whether to question him (Dhruv Narayan) again or not in this regard would depend on the outcome of the investigations currently underway and if something tangible comes out then definitely, whoever the person may be, would be summoned."

"At present it is too premature to say whether he would be called or not," she said.

Meanwhile, sources associated with the probe during the initial phase said the CBI reached the alleged killers, on the basis of call details generated from the tower located in the Koh-e-Fiza area where Shehla was shot dead on August 16, 2011.