China's Supreme People's Court (SPC) on Friday turned down the reprieve sentence for a fund manager convicted in one of the country's biggest insider trading cases.

The decision comes more than a year after procurators protested the lenient penalties handed out by lower courts on Ma Le, a former fund manager with Bosera Asset Management Co. Ltd.

Ma was found guilty of illegally earning 19.12 million yuan (about 2.96 million U.S. dollars) through insider trading, making his case the largest of its kind at the time.

All money would be confiscated and he would be fined an additional 19.13 million yuan, the SPC said in a statement.

In March, Ma was sentenced to three years in prison with a five-year reprieve by the Shenzhen Intermediate People's Court for insider trading.

The Shenzhen court ruled that he had illegally earned 18.83 million yuan and fined him an additional 18.84 million yuan. The figures were lower than those given out on Friday by the SPC, which attributed the gap to a "miscalculation" by the Shenzhen court.

It is illegal for traders to take advantage of non-public information, the maximum sentence for a crime of this kind is five years in prison and fines of up to five times their illegal gains in serious cases. The prison term can be extended to ten years in particularly serious cases.

The Shenzhen court said Ma chose to turn himself in, expressed remorse for his crimes, returned all his ill-gotten gains and paid his fines, but the prosecutors disagreed.

Shenzhen procurators protested the initial verdict in April 2014, labeling the penalty "inappropriate."

The court's ruling was upheld in October by the Guangdong Provincial Higher People's Court, however, prosecutors from the Supreme People's Procuratorate protested it again two months later - this time, to the SPC.

The SPC's No.1 circuit court reopened the case in July.

According to the SPC, Ma's acts constitute "particularly serious offences," and despite the mitigating circumstances the verdict to grant a five-year reprieve was "inappropriate and must be rectified."