"We do not have anything much to say as far as the investigation (into the murder) is concerned," said Deven Bharti, Additional Police Commissioner (Crime) to reporters.
"We are looking into various angles in the murder case, including personal or property angles, which might have led to his killing. We are also checking if the oil mafia had any role in the case," said Bharti.
Dey also toured foreign countries from Apr 20. During his trip he had been to Ireland, Switzerland and England.
"We are also verifying if he also visited Germany. The trip appears to be personal and Dey had travelled alone. He did not share much detail with his family members on the tour," said Bharti said further adding "prima facie, it appears to be pleasure trips."
Dey who was an investigative journalist in the MiD DAY was killed by four unidentified assailants on Saturday, Jun 11.
He had couriered photo copies of his passport and visa documents to the Philippines tourism marketing office located in Delhi minutes before he was killed.
"Maybe, he planned to visit this place (Philippines)," said Bharti.
Mateen Iqbal Hatela and Anwar, the chhota Shakeel gang members who were detained in suspicion with the case had been let off by the police on Wednesday Jun 15. The accused were questioned again by the police.
"Mateen had earlier claimed that he killed Dey at the behest of Anwar, who gave the contract killing. Mateen had also claimed that one Raja D Salvi, who has a criminal background, was with him while executing the crime," said Bharti.
According to Mateen, Raja who hails from Pune and he were on the two bikes along with two other people who he said he did not know. Anwar was in a car when Dey was killed, he added.
"But Mateen's claims did not match with the facts after our verification. Now, we wanted to know why Mateen stated all these things and wanted to mislead the investigations," said the official.
"Due to the high level of secrecy maintained by Dey, we are facing some obstructions on the probe," he said.