Following Kamlesh Tiwari's death, Kiran was unanimously appointed the National President of the Hindu Samaj Party floated by her late husband.
Kamlesh was shot in Naka area of Lucknow on October 18 and succumbed to injuries at a hospital during treatment.
Two deep cut marks were found on his neck and the stabbing was centred between jaws and chest with the wounds were inflicted within 10 centimetres of one another.
Sadiq’s residence has been locked since Monday evening and their whereabouts are not known. Neighbours too were unaware of the developments.
According to police sources, Sadiq had been arrested in rioting cases in Hubballi in 2009-10. He was later enlarged on bail.
On the reasons for the murder, the ATS said primary investigation reveals that they had committed the crime in retribution to purported statements by Tiwari.
Uttar Pradesh Director General of Police O.P. Singh had stated that the accused knew Tiwari as they spent around 30 minutes with him on the pretext of gifting him sweets.
Tiwari (45), leader of the lesser-known Hindu Samaj Party (HSP) who was earlier associated with a faction of the Hindu Mahasabha, was killed at his home in Lucknow on Friday.
The Uttar Pradesh police and their Gujarat counterparts are interrogating the persons taken into custody.