The 21 Indian traders who were arrested last week in the southern Chinese city of Shenzhen on diamond-smuggling charges have been assured that their legal rights will be protected, a Chinese official said on Thursday.

Foreign Ministry spokesperson Jiang Yu said the case was still under investigation, and that Chinese authorities had granted consular access to Indian officials who met with those detained on Wednesday.

“The legitimate rights and interests of those involved will be guaranteed according to law,” Ms. Jiang said, speaking at a regular press briefing when asked about case.

She did not, however, divulge any details of the case, and what specific charges the 21 Indians have been held under.

“The case is still under investigation,” Ms. Jiang said.

The Indian traders were among 33 foreigners arrested in the southern port of Shenzhen on January 8. They are accused of being part of a diamond-smuggling racket. The 21 traders and businessmen are still in

police custody, and have sought legal assistance from a law firm in Shenzhen.

Officials from the Indian Embassy were granted access to them on Wednesday, and were briefed in detail about the circumstances of their arrest.The traders were in good health, officials said.

It is still unclear how long the traders will remain in police custody. The time taken by courts in China to formally file charges -- after which the accused can apply for bail - often varies, from days

to weeks, depending on the case. Cases involving foreigners are, however, usually expedited.