Former prime minister Najib Abdul Razak said BN secretary-general Tengku Adnan Tengku Mansor's wealth was legitimate.

He said Tengku Adnan (pictured above) was a trading partner of tycoon Vincent Tan and held shares in big companies such as The Star, defunct newspaper Watan and Mutiara Telecommunications.

Najib cited the source of this information to "Malaysia's political economy: Politics, patronage and profits" by prominent economist Edmund Terence Gomez in 1997.

"During the 1990s, Malaysia's stock market was bullish. That was when Tengku Adnan increased his wealth.

"At the time, the prime minister was the 'fourth PM' while the finance minister is the 'forever PM-in-waiting'," wrote Najib on his Facebook page today.

Najib was referring to Dr Mahathir Mohamad and Anwar Ibrahim, who are currently both opposition MPs.

"The two of them need to be asked how Tengku Adnan became rich at the time," said Najib.

Tengku Adnan's wealth has come under the spotlight after his previous asset declarations to three prime ministers cropped up during his corruption trial.

In 2001, he had to declare his assets to the prime minister after being appointed as a deputy minister. At the time, he was worth close to RM1 billion.

Tengku Adnan is accused of receiving an RM2 million bribe from a property developer.

His defence team is attempting to prove that the amount was not a bribe but a form of "political donation" instead.

Part of this strategy involves proving that Tengku Adnan was already very wealthy and had no need for an RM2 million bribe.

It was reported yesterday that the MACC has launched a probe into the wealth.