The provided article content is incomplete — only the headline and an unrelated list of other Daily Mail news links were supplied, with the actual report cutting off after the opening words "They didn't expect to be jailed, but security sources reveal the exact r…". No substantive details about the Chawke siblings, the crime they were convicted of, or the security sources' claims about their prospective release are included in the text available.

As a result, key facts such as the siblings' identities, the offence involved, sentencing details, and the specific reasoning behind their expected early release cannot be reliably summarised without access to the full article text.