The 26-year-old wife of a retired businessman, aged 76, is being questioned about her husband's murder after his body was found dumped near a beach in Gambia.
The burnt remains of William West were discovered close to the seaside holiday home in West Africa he shared with his Gambian wife, Kate.
Mr West, who lives in Hastings, East Sussex, was found by Gambian police on Thursday, more than two weeks after he went missing. Police believe he may have been burnt alive.
Mrs West, who married her husband six years ago after meeting him while on holiday in West Africa, was being questioned by Gambian police along with two British men and one West African man. The two British men were later released without charge.
The young woman had previously told the police that her husband had gone missing on 3 July after he went into a shop to buy some cigars during a day trip to the neighbouring country of Senegal.
Mrs West flew back to Britain the day after he disappeared, and reported him as missing to Sussex police, telling officers that she hoped her husband would return to their £750,000 home in Hastings by the end of the week.
Sussex Police contacted the Gambian authorities who set up an investigation.
Mrs West flew back out to Gambia on Tuesday with two English friends to help Gambian police with the investigation. She was arrested on Thursday, along with three other men, after her husband's charred remains were found close to the couple's beach house.
Assistant Superintendent Aziz Bojang, of the police in Banjul, Gambia's capital, said: "His body was very badly burned. We are still investigating the cause of death, but there is a possibility that he was alive when he was set on fire."
The officer confirmed that Mrs West had been arrested. He said: "Kate West is under investigation. She flew to Gambia on Tuesday with two men from Britain. Two men have been arrested along with a man of West African origin. He is not a Gambian."
Assistant Supt Bojang added: "Mr West's remains were found by the beach in the coastal village of Sanyang, where Mr and Mrs West own a property on the beach." Mrs West had travelled back to Gambia on Tuesday with a family friend called David Jenkins.
Earlier in the week Mr Jenkins said they would be speaking to the Gambian police and the British Embassy as part of their efforts to find him.
He described Mr West's disappearance as "bizarre and out of character". "He is a very gregarious person and I've no reason to believe he'd voluntarily disappear. Though he is in his 70s he is a very sprightly person."
Mr West met his second wife, Kate, on holiday in Gambia in 2000 and reported married her after a few months. His first wife Doris died in 1994.
A man who called himself Jim, who has been taking care of Mr and Mrs West's dog at their home in Hastings, said: "I knew William when he was married to his late wife Doris. We have been friends for the last eight years. Everyone was concerned when William went missing. For a guy to walk into a shop to buy some cigars and just disappear beggars belief."
A Sussex Police spokeswoman said: "Police in Gambia have been in touch with officers in Hastings after a body of a man was found. The Gambian authorities will be handling the investigation from now on.
"Sussex Police had Mr West as a missing person, but now he has been found it is closure for us."Reuse content