Kolkata-resident Lalit Jha, 28, the fifth accused arrested late on Thursday in the Parliament security breach case, remained unreachable by phone to his family after calling his brother, Sonu Jha, two days before the incursion to inform him about his plan to travel to Delhi.

Sonu Jha, an electrician, said they came to know that police were looking for his brother from television after two intruders jumped into Lok Sabha from the visitors’ gallery and sprayed smoke in a major security breach on Wednesday.

He added Lalit Jha’s phone was switched off when he tried to contact him multiple times. “All the family members are very disturbed. We do not know why he did this.”

Sonu Jha said they last saw him when Lalit Jha saw them off at the Sealdah railway station. “My father, mother, and I were leaving for our ancestral home in Bihar’s Darbhanga on December 10…on the Ganga Sagar Express from Sealdah station. That was the last time we saw Lalit…he came to the Sealdah station to see us off. On December 11, he called me to say that he would be going to Delhi. I told him to take care of himself,” Sonu Jha said.

Sonu Jha said he stays with my parents in Baguihati on the northern fringes of Kolkata. “…our eldest brother Sambhu stays with his wife and kid nearby. Lalit came to Kolkata around 2002… worked as a private tutor. For some years, he stayed in Burrabazar. That house was dilapidated, so he moved to another place. I am not sure but he was probably staying somewhere as a paying guest,” said Sonu Jha, 22.

He said their father, Devanand Jha, worked as a priest when he stayed at Muktaram Babu Street in central Kolkata.

Sonu Jha said he came to Kolkata around three to four years back. “Lalit came earlier and stayed with our father. I am not sure where he used to stay because I never went to his house. He used to come over to my place.”

Lalit Jha, who has been described as a co-conspirator in the case, surrendered to police before he was arrested late on Thursday. A police officer said one Mahesh accompanied him. Their other associate Kailash was also detained for questioning.

Police said Lalit Jha travelled to Rajasthan by bus, where he is suspected to have destroyed mobile phones before returning to Delhi. He claimed to have stayed with Mahesh in Rajasthan.

Lalit Jha and Mahesh were associated through the Bhagat Singh Fan Club, a social media group the accused were part of.

HT on Friday reported the breach was a well-planned conspiracy going back nearly a year with one of the intruders getting a cobbler in Lucknow to carve 2.5-inch deep cavities in the soles of two pairs of shoes to stuff canisters of yellow smoke he carried to Parliament.

Four of the accused arrested earlier in the case, Sagar Sharma and Manoranjan D, who cleared three layers of security before jumping from the visitors’ gallery and spraying coloured smoke inside the Lok Sabha, and Amol Shinde and Neelam Singh, who shouted slogans outside Parliament, were remanded to police custody for seven days on Thursday.

The incursion on the anniversary of the 2001 Parliament attack was planned for December 14 but was brought forward after Manoranjan received the passes early. It sparked questions about laxity in security

Investigators said an e-rickshaw driver in Lucknow, the son of wage labourers in Latur, a government job aspirant in Jind, an engineering graduate in Mysuru, and a tutor from Kolkata stitched together the unlikely conspiracy.