Although Mr Javid stressed the figure was provisional, his admission gave an indication of the scale of the exercise facing the Home Office.
Under questioning at the Home Affairs select committee Mr Javid said 32 of the 63 cases involved criminals and the other 31 were people who left voluntarily after being sent a letter by the Home Office asking them to leave.More news: Brazil's President Temer calls for FIFA World Cup title
Officials have identified 63 records of people who were deported but may have been entitled to remain in the country under rules applying to migrants and their families invited to settle in the United Kingdom to fill labour shortages.
Although fully entitled to live and work in the United Kingdom, an unknown number of Windrush descendants have been wrongly identified as illegal immigrants and denied basic rights such as healthcare. So far, 526 people have been issued documents confirming their legal right to live in the UK.
All but one left the United Kingdom "voluntarily" after being told to leave, he said.More news: Guatemala inaugurates embassy in Jerusalem amid controversy
The Home Office made the discoveries after analysing 8,000 deportation records of Caribbean-born immigrants aged 45 and over.
"The reason we use the word "could" - it means of the 8,000 records that came up of deportation removals there's so far a focus on the 63 where there's something in their records that indicates they could have been in the United Kingdom before 73 who have been removed or deported".
The United Kingdom could have wrongly deported up to 63 immigrants of Caribbean origin, it emerged Tuesday, in the latest embarrassing revelation of a mounting scandal that has damaged the reputation of British prime minister Theresa May.More news: 'SHE'S PARANOID': Hillary Clinton WARNS Australia of China and Russian 'INTERFERENCE'
But the opposition Labor party and other critics have argued that the Windrush crisis was a effect of an anti-immigrant climate at the Home Office which they said dated back to Prime Minister Theresa May's six years as home secretary between 2010 and 2016. "I also want to know the figures of those who have been detained", she said.