Uncertainties surrounding Shanghai tycoon Chau Ching-ngai have pushed his Hong Kong-listed company, Shanghai Land Holdings, to a record low after a rough week that has seen the firm's stock tumble more than 41 per cent. Shanghai Land , which is 75 per cent-owned by Mr Chau, fell 19.76 per cent yesterday to 34.5 cents after touching an intraday low of 31.5 cents. His other asset, main-board-listed Shanghai Merchants Holdings, also declined yesterday, surrendering 7.14 per cent to close at 26 cents. Mr Chau has pledged all of his 44.1 per cent stake in Shanghai Merchants Holdings to a security company to obtain a loan facility. Mr Chau's listed entities have lost $770 million in market value this week following speculation that the tycoon faces an official probe into irregularities surrounding the $1.5 billion takeover of Shanghai Land in May last year. Company executives on Thursday announced that Mr Chau was not under arrest over the irregularities, but this has done little to stop the downward slide in both stocks. Investors are now curious to see whether Mr Chau will show up at an extraordinary general meeting to be held next week when shareholders will decide whether or not to purchase a privately-owned Shanghai property valued at about $700 million from Mr Chau. 'It looks fishy to me,' said Steven Leung Wai-yuen, director of UOB-Kay Hian. 'An owner mortgaging his shares for financing could indicate that he may have his own financing problem.' Investors shifted 17.48 million Shanghai Land shares yesterday. China Everbright Securities research director Frederick Tsang said: 'It's pretty common for Chinese privately owned enterprises to mortgage shares to raise money.'