Lifeboat crews picked up the first two groups found in July

They are the third group in a month to be found in a dinghy apparently trying to reach the UK from France.

All three incidents have happened on Sundays - the previous two being on 6 and 27 July.

Last week Kent coastguards said they were worried a trend was emerging.

The latest group were picked up by the Pride of Aquitaine ferry just before 0500 BST.

Same make of dinghy

They were seven miles off the coast of Dover at the time, in two rubber dinghies.

The four people in the boats were taken on board the ferry and have been questioned by immigration officials in Dover.

In last weekend's incident three illegal immigrants from Moldova were intercepted in a dinghy 10 miles off Kent.

The three men picked up three miles from Dover on 6 July were in the same make of dinghy and have since claimed asylum.

There was speculation last week that the men may be getting dropped off from motor boats halfway across the Channel and left to paddle to the UK, because their physical condition did not suggest they had been at sea long enough to have crossed all the way from mainland Europe.

It is estimated the men would have had to paddle for about 10 hours to get as close to the UK as they were when they were found.

Dover MP Gwyn Prosser said he had made inquiries to the Home Office but he distanced himself from suggestions that the groups in dinghies may be part of an organised operation.

Dover Lifeboat coxswain Dave Pascall said during July his crew had picked up two unidentified bodies in the Channel.