China purchased a net 234.5 billion yen ($2.9 billion) in long-term Japanese bonds in March, the biggest amount since January 2005, China Business News reported Friday, citing latest data released by Japan's Ministry of Finance.

China began to purchase large amounts of Japan's long-term bonds in 2005 and became Japan's biggest debt buyer for six consecutive years, said the report.

Related readings:  China to float 32.5b yuan in book-entry T-bonds Thursday  China launches private placements of bonds  Building bonds of friendship  China signals ready to invest more in euro zone

Japan's Ministry of Finance said the devastating earthquake in March had caused huge losses to Japan, and large sum of money is needed in post-quake reconstruction, the report said.

Japan's national debt is estimated to hit 1, 002 trillion yen by the end of 2011. According to statistics from the Ministry of Finance, at the end of last year, Japan's national debt totaled 924.36 trillion yen.

According to research by Dai-ichi Mutual Life Insurance in Japan, in 2011, Japan's national debt will hit approximately twice its GDP. Generally, the international community agrees that the safety line for a country's national debt should be no more than 60 percent of its GDP.