A suspect wanted by authorities in the motorway gang-rape case has been arrested and he has confessed to the crime, Punjab Chief Minister Usman Buzdar announced on Monday.

In a tweet, he identified the suspect as Shafqat Ali, and said his DNA had matched with the samples collected from the crime scene.

"Our entire team is also making continuous efforts for the arrest of suspect Abid Ali, which is expected soon," he said, referring to the primary suspect in the case.

"In the light of scientific analysis and investigation of the evidence found at the crime scene, one of the [suspects] ..., Shafqat Ali son of Allah Ditta, resident of Haroonabad, Bahawalnagar district, has been arrested," Punjab Inspector General of Police Inam Ghani said in a statement.

He confirmed that Shafqat's DNA had matched the samples obtained from the crime scene.

He said just as the Punjab Police worked "day and night" to arrest Shafqat, "the fugitive [suspect] Abid Malhi will also be arrested soon and brought to justice," according to the statement.

On Wednesday night, two robbers on the Lahore-Sialkot motorway had gang-raped a mother of two in an area falling within the Gujjarpura police jurisdiction.

Police sources said Shafqat was arrested from the Depalpur area yesterday on the indication of Waqarul Hassan, one of the first two suspects named by police as being involved in the rape case that caused countrywide outrage.

Hassan told investigators that Ali had been carrying out crimes with a man named Shafqat for some time. He said like Ali, Shafqat too is from Bahawalnagar and the two are friends, according to police sources.

The chief minister's tweet came after a second suspect surrendered himself to police and denied his involvement in the crime, police said.

This suspect was identified as Abbas, brother-in-law of Hassan, confirmed Model Town Crime Investigation Agency (CIA) Deputy Superintendent of Police Hasnain Haider. According to the police officer, Abbas refuted his involvement in the rape.

Hassan himself had courted his arrest on Sunday by approaching DSP Haider. He claimed his innocence and requested that his DNA test be carried out to corroborate his claim.

After his surrender, Hassan had also claimed that Abbas (his brother-in-law), who was using his mobile phone SIM, had some links with primary suspect Abid Ali. He had said his brother-in-law would also surrender himself.

Punjab Inspector General of Police Inam Ghani while addressing a high-profile press conference on Saturday had disclosed the identity of the two suspected rapists as Abid Ali from the Fort Abbas area of Bahawalnagar and Waqarul Hassan of Qila Sattar Shah from Sheikhupura district. Their photos were made public along with the announcement of Rs2.5 million reward money for information leading to their capture.

Abid Ali is still at large and police teams are conducting raids to apprehend him.

Father of six, Hassan told the police that he was a motorcycle mechanic and had to visit Lahore frequently to buy spare parts. Police sources said the suspect claimed that he had nothing to do with the gang-rape and Ali's other criminal activities.

Police sources told Dawn Hassan was taken into custody for further investigation and DNA sampling.

First suspects identified

IGP Ghani had told the presser that both the suspects, Ali and Hassan, were identified after police conducted geo-fencing of the entire area and collected fingerprints and DNA samples. The police chief said the DNA database had led to the identification of Ali, as he was previously involved in another rape case, while geo-fencing of the area indicated that Hassan had accompanied him.

He said police had gathered Ali's criminal record and learnt that four mobile phone SIMs were registered in his name that he had used in the past, but all those SIMs were currently inactive. He said another phone number was tracked leading the police to conclude that Hassan was Ali’s accomplice.

IGP Ghani further said police were "95-96 per cent" sure that Hassan was involved in the crime along with Ali, and the former's presence at the crime scene was shown by cellphone data.

However, Hassan's elder brother Shabbir told Geo TV that his brother was not involved in any crime. He said a large police contingent had conducted raids on their house on Saturday afternoon and drove away with their elder brother, Tanvir Hussain, and his son. He claimed Hassan was not home when the police raided as he had gone to a nearby area.

Hassan courted arrest after their family members suffered torture by police, Shabbir alleged.

While replying to a query about Ali, Shabbir said they did not know him. He said Hassan's brother-in-law Abbas was using a SIM registered in his name, but they were unaware whether he had any contact with Ali or not.