The matter came to light when Azhar F. Maniar, alias Shera Chikna, a resident of Kurla West, posted some pictures of a cake which had "Happy Birthday Dawood", written on it.
He also downloaded three pictures of the absconding Mafia don from the Internet and posted comments: "Happy Birthday Boss" and tagged it Don Mumbai, Sherkhan, and Don Khan.
The posts went viral on social media networks and a Marathi newspaper even published a report on it two days ago.
Thereafter police said that Shera Chikna threatened the reporter, Mohsin Shaikh, and then went underground, but AEC sleuths managed to track him down.
During interrogation, Shera Chikna claimed that a month ago, he had celebrated the birthday of a friend of his, Dawood Hashmi of Bandra, in a posh restaurant in Bandra Kurla Complex.
At that time, he said that he had clicked pictures of the birthday cake with the greetings, "Happy Birthday Dawood", which he posted on December 25, the eve of the don Dawood's birthday (December 26), to gain popularity on the social networks.
The pictures went viral on WhatsApp groups, Facebook, YouTube and other social media sites, which alerted the AEC to launch a probe.
Police have registered a FIR against Shera Chikna for threatening the journalist and are probing whether the accused and his friends have links with the mafia don.
( With inputs from IANS )