New data raised doubts of "rampant misuse of legacy data", the Assam government said.

Draft data of the National Register of Citizens or NRC in Assam showed many people in the border districts had been included through "'rampant misuse of legacy data", the state government claimed on Thursday, once again alleging irregularities in the list being prepared to weed out illegal settlers.

Last month, the Supreme Court had turned down a request by the centre and Assam government to have up to 20 per cent of the names on the draft NRC, particularly in districts bordering Bangladesh, checked again.

The ruling was given after Prateek Hajela, the coordinator for the NRC, told the top court that that 27 per cent of the names in the draft NRC had been verified once again.

"Why did Hajela do 27 per cent re-verification without informing anyone? He didn't even inform Supreme Court," Assam BJP president Ranjeet Dass told NDTV, adding that his party doubted the data because no advertisement was issued for NRC re-verification.

On Thursday, Assam cabinet minister and government spokesperson Chandramohan Patowary submitted a report in the assembly and said "data analysis" proved their allegations of an "erroneous" NRC.

This was the first time that the district-wise data of people excluded and included in the NRC has been made public since its release in July last year.

According to the government's data, 87.85 per cent of the total 3.29 crore applicants were included in draft NRC, leaving out about 40 lakh people or 12.15 per cent.

Minority-dominated Hojai district with 32.99 per cent and Darrang district with 30.90 per cent have the highest number of people left out. Majuli with 1.62 percent has least people left out of draft NRC.

The Assam government says the point that proves its claim is that in all the four districts bordering Bangladesh, the rate of exclusion is lower than districts where population of indigenous communities is more.

For example, in Dhubri district bordering Bangladesh, dominated by migrants, only 8.26 per cent people were left out whereas in tribal-dominated Karbi Anglong, 18.31 per cent people were left out of the draft NRC.

This raised doubts of "rampant misuse of legacy data", the government said. Legacy data refers to the 1951 NRC and electoral rolls up to midnight of March 24, 1971 which can be used to prove an applicant's antecedents.

Assam, which had faced an influx of people from Bangladesh since the early 20th century, is currently updating its NRC which was first prepared in 1951. The Supreme Court last month extended the deadline for the final publication of the list from July 31 to August 31.