British police investigating the murder of 46-year-old millionaire businessman Amarjit Chohan and the disappearance of his wife, two young sons, and mother-in-law suspect that he may be an early victim of the latest drug war to hit the United Kingdom.

Weeks after the family was reported missing from its home near London's Heathrow airport, Chohan's body was found floating near the Bournemouth pier.

The police have named two suspects for his murder and are liaising with their French counterparts to locate them in France.

At the weekend, a 38-year-old man from Portsmouth, named Peter Douglas Rees, was remanded to custody after being charged with Chohan's murder. He is not one of the two men who had earlier been named.

Police believe Chohan may have been involved in the smuggling of khat (scientific name: catha edulis), a narco-drug native to East Africa that is legal in the UK, but is banned in Europe, the US and Canada. It has an annual turnover of £150 million. In the US alone, some 22 British nationals have been arrested so far trying to smuggle khat into the country, but Chohan may be the first murder victim of the trade.

Levels of violence have gone up as profits have soared. In the UK, a bunch of khat can be purchased for £3, but in the US the same bunch fetches £30. A single journey across the Atlantic can generate profits of £15,000 after deducting the cost of the flight and payment to the courier.

At Chohan's CIBA freight services company in the London suburb of Southall, employees still believe their annual turnover of £4 million came from importing foodstuffs direct from Africa. No one is willing to discuss khat or their dead boss.

Police are now in possession of documents that make them suspect Chohan was under pressure before he was killed.

The first sign of trouble was a letter sent by Chohan and received by staff last February 14. In it he said he had had enough and was returning to India.

Two days later, the company's operations manager received a similar letter, also composed on a computer, which aroused suspicion as Chohan always wrote his letters by hand.

The following month, a letter sent with a Calais postmark said the family was in France on its way to India, but this was patently untrue as Chohan's passport was with the home office while his wife had applied for British citizenship.

This last letter included a power of attorney handing over control of the company to his lorry driver, Kenneth Regan. Both Regan and an associate, William Horncy, have been named by police as suspects in the Chohan murder. Both men have fled the country.

Police have confirmed that Regan was a convicted money launderer and had made a fortune selling false passports to criminals.

After a second post-mortem on Chohan's body, medical experts now believe he may have been strangled before the rest of his immediate family were murdered. They include his mother-in-law, who had made a booking to return to India only days before she disappeared.