Fallen Chinese politician Bo Xilai has told the third day of his trial his convicted wife is 'insane' after her evidence contradicting his robust defence against corruption charges.

The 64-year old former Communist Party chief of the southwestern city Chongqing, faces charges of bribery, corruption and abuse of power and will almost certainly be found guilty.

Bo called his wife insane after her video and written evidence yesterday said he knew of money and a villa in the French Riviera that prosecutors say were given to the couple by a businessman friend.

Gu Kailai's testimony directly contradicted Bo's robust defence on Thursday and appear to set him up to be found guilty. 

Bo dismissed Gu's testimony as the ravings of a madwoman.

Gu has been jailed for the murder of British businessman Neil Heywood in November 2011, the crime which eventually led to Bo's downfall.

Bo was a rising star in China's leadership circles when his career was stopped short last year by the scandal involving Gu.

On Thursday, observers said the court proceedings were probably scripted and that Bo could receive a pre-arranged sentence in exchange for limited outbursts that would show that the trial was fair, appeasing his followers.

Bo could face the death sentence though a suspended death sentence is more likely, which effectively means life imprisonment, or a 20-year term.

The verdict is likely to be in early September, CCTV said.