The search for the British crew of the yacht Cheeki Rafiki will be suspended if nothing is found by tonight, the US Coast Guard has said.

Albert Davey, 76, of Longleaze, Royal Wootton Bassett, and his family have been hoping that nephew Steve Warren would be found even though the yacht has been missing for a week off Cape Cod.

Mr Davey, a retired NHS worker who used to be based at the old Burderop Hospital near Wroughton, has been in Bridgwater, Somerset, this week to be closer to his wife’s family.

Captain Anthony Popiel, chief of response at the 1st Coast Guard District, said he had spoken to the family of the four missing sailors to tell them that the search would be suspended at midnight.

Capt Popiel said: "I informed them that the search would continue throughout the night and into tomorrow. If by midnight tomorrow (5am Saturday UK time) there are no further developments to indicate search efforts would locate the crew alive we will suspend the search."

"It is only after deepest consideration that we suspend active search efforts.

"With sincere compassion for the families of these four men, our thoughts and prayers are with them all during this difficult time."

Coastguard officials have informed the British Consulate of their plans but are continuing to search for the missing men - experienced captain Andrew Bridge, 22, from Farnham in Surrey, and crew members James Male, 23, from Southampton, Steve Warren, 52, from Bridgwater, Somerset, and Paul Goslin, 56, from West Camel, Somerset.

Capt Popiel said: "Our focus right now however remains with this very active and very dynamic search. We will always put forth utmost efforts to find and rescue those in peril at sea."

Searchers from the US Coast Guard, the US Air Force, the Canadian military and the RAF, as well as a number of commercial vessels and volunteers, have combed more than 17,000 miles of ocean in the hunt for the Cheeki Rafiki's crew. The yacht is thought to have sunk around 620 miles east of Cape Cod last Thursday.

Debris found in the area of the Atlantic Ocean where the yacht disappeared did not belong to the stricken vessel, coastguard officials said yesterday.

Capt Popiel said: "Unfortunately we have had no sightings thus far and have concluded that none of the debris or objects located during the search have correlated to the Cheeki Rafiki."

More rescue vessels would arrive at the scene today, he said. The coastguard cutter Vigorous will arrive on scene within the next few hours and a US navy warship has already arrived in the search area and is using its helicopter to carry out searches.

Capt Popiel said: "In total, efforts since resuming the search have covered more than 17,500 square miles of ocean."

Search conditions yesterday were described as "favourable", with winds around 20 knots and seas of roughly 6ft to 8ft.

The Maritime and Coastguard Agency (MCA) said it understood and supported the "extremely difficult decision" by its US counterpart to suspend the search, and thanked the coastguard for its "extraordinary efforts" to find the missing vessel.

An MCA spokesman said: "We understand and support the extremely difficult operational decisions that the US Coast Guard is taking and the rigour with which they do so.

"Our focus is on the search... and our thoughts are with the families of the missing men at this time."

The MCA also urged volunteers in small vessels hunting for the missing yacht not to enter the search area over safety fears because of forecasts of bad weather.

The spokesman said: "We would urge owners of small craft not to venture into the area to conduct their own search operations taking into account the forecast decrease in weather conditions and the loss of two yachts in this region in the past fortnight."

Foreign Office Minister Hugh Robertson also spoke to the families of the missing sailors last night to inform them of the US Coast Guard's decision to suspend the search, saying it had gone "above and beyond" in its efforts to find them.

Mr Robertson said: "I know that, despite there being no further sightings of the Cheeki Raffiki or its crew, any decision to suspend the search will be incredibly difficult and will only be taken after the most serious deliberation."