Krishna, who is on a four-day official visit to China, met the families of the Indians, who were arrested in the southern Chinese city of Shenzhen in January, sources said.
While 20 Indians have been charged with diamond smuggling, one has been charged with money laundering.
India has again sought consular access to meet the Indians and has also requested Chinese authorities to allow them to meet their immediate family members, sources said, adding this would happen soon.
The sources said the Minister assured the families that he would the raise the issue during his talks with Premier Wen Jiabao and Foreign Minister Yang Jiechi. Krishna is scheduled to meet Wen and Yang later in the day.