China on Tuesday defended its presence and investments in the Democratic Republic of Congo after a rebel leader there demanded commercial contracts between the two nations be reviewed.

"China's business activities and investment programmes in DR Congo are based on mutual benefit and joint development," foreign ministry spokesman Qin Gang told reporters.

"Chinese companies, apart from cooperation in sectors like mining and natural resources, are also engaged in non-profit areas."

"We hope that these mutually beneficial cooperation programmes will move forward."

Qin's comments came after Laurent Nkunda, a rebel leader who claims to be protecting the Tutsi population in the country's war-torn east, asked the contracts be reviewed as part of a list of demands put to a special UN envoy.

The east of DR Congo has seen months of heavy fighting, with government forces and Nkunda's troops clashing repeatedly since August in violation of a January ceasefire. An estimated 250,000 people have been displaced.

The country has increasingly been reliant on borrowing money from China -- a situation that drew the concern of the International Monetary Fund in September.

Beijing has been investing heavily in the Democratic Republic of Congo in recent years.

It lent the central African country an estimated nine billion dollars in May to restore its infrastructure and revive the mining industry.

It also made a 35 million dollar investment into the Congolese postal service last January.