Sharif said in his statement that 1,150 DNA samples were collected and matched with samples taken from Zainab's body.
There has been no immediate comment either from the accused or his lawyers.
The committee had also passed a resolution strongly condemning abductions, rapes and murders of innocent minor children across Pakistan and condemned the murder of Zainab in Kasur and Asma in Mardan.
It is worth mentioning here that Zainab's father while talking to media on Tuesday also said that this was not the occasion for clapping, referring to Shahbaz Sharif's action of commending police officials who arrested the killer and rapist.
The rape and murder of Zainab Ansari was the 12th such case in Kasur district in the past year, according to local media reports. He was apprehended after DNA samples picked from the girl's body matched his. The organisation gathers figures by tracking reports in national media, but Munizae Bano - Sahil's executive director - also explained that most cases go unreported.
Imran was held some 14 days into the probe and was earlier arrested during preliminary investigation on January 9 but was released after he "suffered" of a attack. He said the suspect was arrested from Pakpatan district of Punjab.
According to the initial post-mortem report, the minor was strangled to death after being raped multiple times.
Reports say the suspect named Imran is a resident of the same area and lived in close proximity to the house of Zainab's aunt. CCTV footage of the day she was abducted showed her walking off calmly with a man identified as her kidnapper. "If our daughters are not secure, then we ourselves are not secure."Khan, the spokesman for the Punjab provincial government, conceded that police did not investigate the earlier deaths as thoroughly as Zainab's.He said he had "no reason to deny" accusations by the parents the police should have acted sooner".