A British man is "not a suspect" in the murders of his wife - a former teacher at a Midland school - and baby daughter who were killed in the United States, police said last night.

Neil Entwistle is believed to have flown back to the UK from Boston, a day or two before the bodies of his wife Rachel and daughter Lillian were discovered under a pile of blankets in a bedroom at their home. Both had been shot.

A statement by Nottinghamshire Police last night said the 27-year-old was a "potential witness" by US authorities and there were no extradition proceedings.

"On that basis the police in England and Wales have no legal powers to take executive action. In the circumstances it is not our role to comment on speculation regarding his whereabouts," it added.

Four plainclothes state detectives were said to have boarded a plane from Boston to Britain on Wednesday night. It is understood Mr Entwistle, originally from Nottinghamshire, is in the UK and has been in contact with American officers investigating the double murder.

American-born Mrs Entwistle taught at the St Augustine's Catholic High School in Redditch, Worcestershire, until last year, when she returned to the States with her husband.

Mrs Entwistle, aged 27, and her nine-month-old daughter Lillian were found dead on Sunday night in their 2,700 dollar a month (#1,534) rented five-bedroom home in the quiet town of Hopkinton in Massachusetts.

Mr Entwistle had been unemployed since moving to the US and is believed to have had several job interviews set up for last Friday, which he failed to attend.

District Attorney Martha Coakley said they believed he left the US late on Friday or early on Saturday. Several sources in the US confirmed he was on a flight from Boston to London on Friday.

Ms Coakley said investigators had developed a rough timeline that placed Mr Entwistle in Massachusetts when the shootings happened, but insisted he was still only "a person of interest" in the case.

She said the state medical examiner's office's "best guess" was that Mrs Entwistle and Lillian died some time between 1am on Friday and early on Saturday.

But she added: "It's still kind of a blurry timeline, whether he was still in the country or not when the shooting occurred. It does not let him off the hook."

However, last night's police statement confirms that US authorities see Mr Entwistle primarily as a potential witness to the shootings, rather than as the main suspect.

The couple did not appear to have financial troubles and were paying their rent, Ms Coakley said. The small-calibre weapon with which the shootings were carried out has not been recovered.

She added that investigators were "looking into" widely circulated allegations that Mr Entwistle may have been involved in internet scams.

Reports claimed he ran a website offering what appeared to be "get-rich-quick pyramid schemes" linked to internet pornography, prom-ising thousands of dollars in profits for a small joining fee. ..SUPL: