Noida, May 23: In a sensational turn, police today arrested Rajesh Talwar for allegedly killing his daughter Arushi and domestic help Hemraj in their residence last week possibly because both of them knew about his extra-marital affairs and the two victims themselves shared a close relationship.

Exactly a week after the girl's murder came to light, Meerut Zone Inspector General Gurdarshan Singh told a press conference that Talwar was arrested after enough evidence was gathered, including the "strenuous cover-up" attempts by the dentist.

He said Talwar first killed the domestic help on the terrace of the house in the small hours of May 16 and then came down to kill his daughter after having some whiskey.

Singh said investigations were on and parried all questions whether any more arrests have been made in the case.

There have been reports that Nupur, wife of Talwar, also a dentist, and his doctor colleague Anita Durrani have been detained in connection with the twin murder.

"Investigations are on and we have revealed to you details about which the probe is over. We have not done the arrest solely on the basis of confessions. We will not arrest a person if we do not have sufficient evidence," Singh said replying to a barrage of questions.

After taking Talwar on remand, he said police would take him out for recovering the weapons used in the murder -- a sharp edged weapon and possibly a hammer-like object.