Police want to make the cobbler a witness in the case, PTI reported.
Delhi Police has sought the help of its Lucknow counterparts to trace a "cyclist cobbler" who created cavities in the shoes of Parliament security breach case accused Sagar Sharma and Manoranjan D to fit smoke canisters in them, PTI reported quoting its sources.
Police want to make the cobbler a witness in the case, they said.
Sagar first tried to modify the shoes himself but approached the cobbler, who visited Alambagh in Lucknow on a bicycle, after he was unsuccessful, the Delhi Police sources said.
A Delhi Police team visited Lucknow to search for the cobbler earlier this month.
In a major security breach on the anniversary of the 2001 Parliament terror attack on December 13, Sagar and Manoranjan jumped into the Lok Sabha chamber from the public gallery during Zero Hour, released yellow smoke from canisters and shouted slogans before they were overpowered by some of the MPs.
They gained entry into the Parliament using visitors' passes facilitated by two-term Lok Sabha member from Mysuru Pratap Simha.
During interrogation, Sagar revealed that he tried to design shoes with a cavity after he found out that they were not checked during entry into the Parliament, the sources said.
"When he did not succeed in his attempts, he went to a cobbler in Alambagh. He has told the interrogators that he bought two pairs of shoes for Rs 595 each from a shop near his house and approached the cobbler, who visited Alambagh on a bicycle," a source said.
"The cavity was found created by cutting the inside sole of the left shoe. The thickness of the sole of shoes is also found increased by affixing additional rubber sole at the bottom to support the cavity. The inside sole of the right foot shoe was also found partly cut," according to the FIR.
A team of the Delhi Police Special Cell visited Lucknow earlier this month to search for the cobbler but was unable to trace him. The team also questioned several cobblers in Alambagh based on disclosures made by Sagar during his interrogation, the sources said.
Delhi Police wants to make the cobbler a witness in the case and is now taking the help of its Lucknow counterparts to find him, they said.
During its visit, the team recovered a pair of shoes, shoe soles and a ruler for measuring shoe size from Sagar's house in Ramnagar in Lucknow's Alambagh, according to the sources.
A diary and some books on freedom fighter Bhagat Singh were also recovered from his house.
Sagar's family has told the investigators that he admires Bhagat Singh. His social media profile also showed that he used to share content related to Bhagat Singh and Cuban Marxist revolutionary leader Che Guevara.
Earlier, police said the accused persons in the Parliament security breach case wanted to replicate Bhagat Singh's act of throwing bombs inside the Central Assembly during British rule in India.
A class 12 pass-out, Sagar worked as an e-rickshaw driver in Lucknow. His father Roshan Lal Sharma is a carpenter and his mother is a housewife.
The police team has already recorded the statements of Sagar's family members, friends and the owner of the shop from where he bought the shoes.
Besides Sagar and Manoranjan, Delhi Police have arrested four people -- Neelam, Amol Shinde, Lalit Jha and Mahesh Kumawat -- in the Parliament security breach case.
All six have been booked under the stringent Unlawful Activities (Prevention) Act.
(Except for the headline, this story has not been edited by NDTV staff and is published from a syndicated feed.)