Cervantes daughters Dimple Bermejo and Marichu Duque claimed that their fathers continued demand for the BIR to pay him millions in reward money could have triggered his slay.
The two daughters claimed that Cervantes, alias Ric Hernandez, had given information about tax evaders to the BIR, including an insurance company where he formerly worked.
They added that Cervantes was in Manila to monitor the progress of the bidding of a small island, which he suspected to be rigged in favor of an insurance firm.
Before his death, Cervantes talked with officials and reporters of a daily broadsheet to expose the said bidding and other anomalies at the BIR.
Bermejo and Duque disclosed that the BIR owed their father millions in reward money but Cervantes repeated demand for payment fell on deaf ears.
They said a BIR commissioner offered him P6 million to keep his silence on the issue but Cervantes refused.
Superintendent Ericson Velasquez, Mandaluyong City police chief, said they are still verifying the claims of Bermejo and Duque with the BIR.
He noted that the statements of the two sisters cannot hold water in court.
"We are at a loss as to who wanted him dead," Velasquez said.
Meanwhile, Cervantes neighbor Manuel Paguia claimed he and his friends noticed the green Mitsubishi Lancer in their neighborhood several days before Cervantes was gunned down by two armed men at the corner of F. Ortigas and Aquino streets last May 2.
But Paguia and a friend, a certain Tikboy, cannot remember the faces of the two men inside the vehicle nor the cars plate number.