Property tycoon Nicholas Hoogstraten has strengthened his ties with the regime of Robert Mugabe by becoming the biggest foreign investor in Zimbabwe.

Hoogstraten owned more than 400 homes in Brighton and Hove at the height of his power but his fortunes dipped after he was arrested following the death of his business rival Mohammed Raja, in July 1999.

Mr Raja was shot dead at his home in Surrey by two men alleged to be Mr Hoogstraten's henchmen. They are serving life for murder.

The tycoon, 59, was given a ten-year jail term at the Old Bailey in 2002 for manslaughter but his conviction was later quashed on appeal.

He has now built up his stake in Zimbabwe's NMB bank to about 30 per cent.

NMB Bank was valued at £70 million when it was floated in 1997 and was ranked among the top 30 banks in sub-Saharan Africa.

But last year its fortunes plummeted after its founders - supporters of the opposition Movement for Democratic Change - were forced to flee Zimbabwe.

They were accused of illegally moving currency abroad and Mugabe's government froze all their assets.

Hoogstraten, a key financier of Mugabe's ruling Zanu PF party, owns several large farming estates in Zimbabwe, which Mugabe spared from seizures during his chaotic land reform programme.

Hoogstraten also has a controlling stake in Wankie, the country's largest coal mine.

Last week Hoogstraten shocked what remains of Zimbabwe's financial community by turning up at the annual meeting of NMB and announcing he had become the largest shareholder.

The Raja family won High Court rulings which resulted in Mr Hoogstraten being fined £1 million for non-disclosure of assets.

They were pursuing a £5 million claim their father had been making against Mr Hoogstraten over business deals before his death.

The tycoon, who once boasted he was worth £500 million, was granted £1.12 million in legal aid for representation in his murder trial.