Mainland police who raided the North Point flat of a Hong Kong couple standing trial in Zhaoqing should be punished for gathering evidence illegally, the couple's defence lawyer said. And the couple - who face the death penalty if convicted of corruption charges - should be acquitted because the case against them has been tainted, he argued. Lawyer Chen Xiaofeng made the call in a submission to the Zhaoqing City Intermediate People's Court, which is expected to pass a verdict this month on charges that Su Zhi-yi, 66, and Kam Shuk-yee, 56, pocketed $4 million of government funds. Su is accused of being a public officer assigned by the Zhaoqing City Government to run Paraway Industries in Hong Kong between 1988 and 1994, while his wife oversaw the accounts. Prosecutors claim the firm is state-run, while the couple say it is private. The prosecution told the court last month that Zhaoqing Public Security Bureau officers seized company account books from Su's home in North Point on October 28, 1995. The revelation sparked concerns in Hong Kong. Democratic legislator James To Kun-sun is planning to call a special Legislative Council security panel meeting to discuss the case. In an editorial this week, the pro-Beijing Hong Kong Commercial Daily claimed the people who came to Hong Kong to take the account books were Zhaoqing City economic officials and Paraway staff. But the defence submission says the prosecution presented illegally obtained evidence and had failed to prove the company at the centre of the case was state-owned. Mr Chen's submission said: 'During the trial, public prosecutor Zhou Shu repeatedly told the court that the account books related to Paraway Industries were seized from Su Zhi-yi's home in Hong Kong. 'Also, the main procurator, Fu Yeming, told the court a warrant had been issued and this was legal, and he then started a debate with the defence lawyers on this question. Obviously, the procurator has revealed the illegal act of the Zhaoqing public security officers. Their illegal act was not confined to just one occasion. This is a very serious breach of the law.' Both Mr Chen and another defence lawyer, He Minghai, said they believed the 'illegal' act was committed by individual Zhaoqing officers and not officially sanctioned by Public Security Bureau chiefs or the Zhaoqing Government. Mr Chen said in his submission that the security and prosecution officers who broke the law should themselves be brought before the court and penalised. The couple's daughter, Su Suet, said she was arrested with her parents on the same day in 1995 and was taken to the Hong Kong flat by public security officers and Paraway staff. Ms Su also alleged her mother was escorted to Macau by Zhaoqing police to force her to sign over a flat in the enclave in January 1996. Her father was alleged to have been escorted by Zhaoqing police to Hong Kong to remove personal belongings from his bank safe box and home in the same month. Hong Kong Island Regional Crime Unit superintendent Man Chi-hung said officers were trying to verify entry records with the Immigration Department, while the Security Bureau said it was discussing the case with the Guangdong authorities.